That's good idea. I'll add a "To Splash or Not To Splash?" section soon. With regards to Cursecatcher... I definitely consider him part of the deck's core, so I think I'll do that.
Unrelated: does anyone know how to add the show/hide block and the rating bar pieces of code? I'd like to streamline the appearance of the primer.
This section will describe some of the more common named decks in the current Modern metagame, and how Merfolk matches up against them. It will also contain suggestions on good cards to sideboard in or out during the match. All of the recommendations will be made with mono-U Merfolk in mind, as that is the most competitive variant of the deck.
Established:
Affinity (Hardened Scales) General Impression: Bad matchup Synopsis: What makes this matchup tough are that they have a wide variety of haymakers that can escalate things out of control. Walking Ballista can both threaten our life total and keep the board clean, whereas Steel Overseer or Arcbound Ravager can get out of hand with even a small amount of support. Pair them with even a single Hardened Scales or Animation Module, and the snowball gets too hard to stop. I have found that the best chance we have in the matchup is to prioritize interacting with them early and often, as opposed to developing our own board, and then transitioning into creature beatdown when they get low on threats. Counterspells come up bigger here than they do for other Affinity variants, as this deck often spends its first turns in setup mode. Catching a Ballista or Ravager coming in can sometimes be the difference between winning and losing. Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Chalice of the Void), hand disruption (Vendilion Clique, removal (Dismember, Gut Shot). Side out: Slow haymakers (Master of Waves), small value creatures (Benthic Biomancer).
Bogles General Impression: Close matchup Synopsis: This matchup is often tough in Game 1, as many Merfolk maindecks aren't well suited to interacting with enchantments and hexproof creatures. The good news is that (depending on the contents of your sideboard) the post-board games get significantly easier, once you can actually interact with their enchantments. A thing to note is that Daybreak Coronet can effectively be countered if you can deal with the other Auras on the creature while it is on the stack, which means that the likes of Echoing Truth come up big here. Dedicated hosers like Chalice of the Void and Spellskite are also very strong, as is putting a lid on their white mana with Spreading Seas. If you can scratch together enough disruption, Merfolk has a quick and evasive clock to put the game away. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Spell Pierce), hand disruption (Vendilion Clique), land hate (Sea's Claim), redirect effects (Spellskite). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), slow haymakers (Master of Waves).
Burn General Impression: Good matchup Synopsis: Defense is the name of the game here. They're going to come out fast and furious with cheap creatures and burn spells, so your job is to preserve your life total as much as you can until you can turn the corner. Countermagic on their burn spells is generally very good (especially on effects that target both your creatures and you, like Searing Blaze or Searing Blood), Merfolk Trickster and Harbinger of the Tides (mostly when backed up by an Aether Vial) can buy time and provide bodies to either attack or trade with, Silvergill Adept trades with any creature on their side while also drawing you a card, and Master of Waves is your midgame haymaker that you're usually trying to work towards. If you are on the play or if they have a land-light hand, Spreading Seas can slow them down signifcantly and sometimes even lock them out of casting spells. Some final notes: Burn pilots occasionally play Ensnaring Bridge in their sideboard, so side in some nonland permanent bounce effects if you see it played against you. Also, be careful about blocking with Master of Waves postboard without countermagic backup: Skullcrack turns off protection's damage prevention effect. Side in: Countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), land hate (Sea's Claim), redirect effects (Spellskite), tapdown effects (Tidebinder Mage). Side out: Value cards (Benthic Biomancer), sorcery-speed bounce (Harbinger of the Tides).
Death & Taxes (WX) General Impression: Good matchup Synopsis: This Vial deck invests a lot of resources in messing with opponents' noncreature spells with effects like Thalia, Guardian of Thraben and lands with the Leonin Arbiter + Ghost Quarter 1-2 punch; unfortunately for them, Merfolk is extremely resilient to being attacked on both of those fronts. Furthermore, our creatures outmuscle theirs pretty readily when backed up by a Lord effect or two. The only real way you can run into trouble is if they manage to wall you off with Thalia and Blade Splicer effects and chip you to death with flyers like Flickerwisp and Restoration Angel. To avoid that, save your Tricksters for buying time or outright sniping flyers out of the sky. You can also potentially Harbinger them back if giving them a re-do on their enter-the-battlefield effects doesn't put you in too bad a spot. You can also use Seas effects to waltz past their blockers and crash in for the damage you need to race. Overall, this is a matchup that rewards tight play (and starting with a turn 1 Aether Vial), but more often than not we have the edge. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot). Side out: Countermagic (Deprive, Force of Negation).
Dredgevine General Impression: Close matchup Synopsis: This deck is capable of some very explosive starts that can beat more or less anything, but the average hand is something you can handle, provided you draw the right mix of disruption (namely Harbinger of the Tides and Merfolk Trickster) and pressure. Master of Waves is generally a big help in this matchup, as they have few ways of removing it and it provides a large board to turn the corner with. This deck uses its graveyard quite extensively, so postboard hate will come in very handy. If you are in Game 1 or have not found your hate, you may want to have one of your Merfolk take one for the team in order to exile Bridge from Below and keep their Zombie-generating shenanigans (via Viscera Seer and/or Greater Gargadon) in check. Last but not least, watch out for a Goblin Bushwhacker putting out a bigger board than what you were equipped to handle. Side in: Bounce (Echoing Truth), countermagic (Chalice of the Void), graveyard hate (Grafdigger's Cage, Relic of Progenitus). Side out: Countermagic (Deprive, Force of Negation), small value creatures (Benthic Biomancer).
Eldrazi & Taxes (WBC) General Impression: Close matchup Synopsis: Unlike its mono-colored cousin, this deck possesses the right mix of hand disruption (Tidehollow Sculler and Thought-Knot Seer) and removal (Fatal Push, Path to Exile, and Wasteland Strangler) to actually pick apart your board synergies and clock you if left unperturbed. However, it's usually a bit of a slow starter, so stacking Lords and putting lots of boots on the ground can sometimes put them in situations where they are too far behind to come back. Alternatively, their manabase is pretty gnarly (this is effectively a 3-color deck without fetchlands), which means that a Spreading Seas on the right land can hurt them pretty badly. Master of Waves allowing you to go super wide to break board stalls can also be a big help, provided you can keep it on the battlefield. As usual in Vial pseudo-mirrors, getting the namesake artifact in your opener is a plus, and countermagic is generally unreliable. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), redirect effects (Spellskite), removal (Dismember). Side out: Countermagic (Deprive, Force of Negation).
Elves (GX) General Impression: Bad matchup Synopsis: No sugarcoating it; this is a tough matchup. In order to have a chance, you need to keep their board from spiraling out of control by putting the clamps on their big mana producers (Elvish Archdruid and Heritage Druid) while effectively clocking them with a Lord-and-Seas-based offense. If you don't find that right mix, you might find yourself getting run over by Elves backed by either a mass of Lords (the Archdruid and Elvish Clancaller), Ezuri, Renegade Leader, Shaman of the Pack, or sometimes even Craterhoof Behemoth. If you do find yourself in a board state where things are more or less stable, try to counter or otherwise deal with these major payoff spells, as well as the card advantage effects (Collected Company, Lead the Stampede, and occasionally Beast Whisperer) which keep the chain moving. Again, far from an easy matchup, so you need things to break just right in order to win. Side in: Bounce (Echoing Truth, Hibernation), countermagic (Chalice of the Void), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage). Side out: Countermagic (Force of Negation), slow haymakers (Mater of Waves).
Faeries (UBX) General Impression: Good matchup Synopsis: Because this deck relies on establishing threats like Bitterblossom early and then playing a control game to back them up, you generally have a couple of turns to get a board state going before you have to worry about what they're doing. If you can get some offense going in that time, you'll find that their clock is usually a bit too slow to race you. As this is a blue deck that can put blockers in front of your attackers, getting (and keeping) Islandwalk is among your highest priorities. Keep them on the back foot (hands with Aether Vial generally have an easier time of this), interact with their planeswalkers (either on the stack or on the board), and you should win. Side in: Bounce effects (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique). Side out: Single-target bounce (Harbinger of the Tides), Seas effects (Spreading Seas).
Goblins General Impression: Close matchup Synopsis: This deck will come at you all guns blazing, so it's imperative that you put blockers in front of their attackers and slow things down until they run out of gas and you can flip the script. Preserving your life total is very important, as they have a lot of ways to push damage through. You should usually, if not always, trade cards for life if given the choice to do so. A big Master of Waves is often your best way to win here, so try and line that up as best you can. If your opponent runs Goblin Piledriver, don't forget that a Mutavault can block it, and that Dismember can kill it. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), counterspells (Chalice of the Void), redirect effects (Spellskite), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage). Side out: Counterspells (Deprive, Spell Pierce), Seas effects (Spreading Seas).
Hollow One General Impression: Good matchup Synopsis: As with many of the more aggressive decks in the format, defense is the name of the game. Their big haymaker creatures (Hollow One, Tasigur, the Golden Fang, and Gurmag Angler) are vulnerable to bounce effects, so Harbinger of the Tides is very strong. They run quite a few removal spells (especially postboard), so be careful about committing to attacks that can get blown out by a single Bolt or Push. The easiest way to win this matchup is usually to weather the early storm, and work your way up to a big Master of Waves they both can't attack through and can't adequately defend against. It's also a pretty graveyard-dependent strategy, so postboard graveyard hate will do well. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), counterspells (Chalice of the Void), graveyard hate (Grafdigger's Cage, Mistcaller, Relic of Progenitus), removal (Dismember). Side out: Value creatures (Benthic Biomancer), countermagic (Deprive), land disruption (Spreading Seas).
Humans (5c) General Impression: Close matchup Synopsis: As with most Vial deck pseudo-mirrors, who can establish control of the board through fast deployment and tricks has an advantage here. Hands with Aether Vial will generally perform better than ones without it. Because Humans is a bit faster but lacking in resilience, Merfolk's job is often to blunt their initial rush with Merfolk Trickster and Harbinger of the Tides, then turn the corner with Lord-stacking or by going very wide with Master of Waves. Countermagic is at its worst in this matchup, because they feature Aether Vial and Cavern of Souls to bypass it. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique, removal (Dismember, Gut Shot, tapdown effects (Tidebinder Mage), Vial hate (Mistcaller). Side out: Countermagic (Deprive, Force of Negation).
Infect General Impression: Close matchup Synopsis: This is one of the fastest decks in the format, so playing defense is a must. Interactive creatures like Harbinger of the Tides and Merfolk Trickster go a long way in this matchup, as do cheap counterspells like Spell Pierce or lockdown cards like Chalice of the Void (Infect is usually well-prepared to fight through removal - counterspells are significantly harder for them to overcome). Block their creatures whenever possible, try to kill or bounce what you can't block, and then turn the corner with Lord-fueled crackbacks. Despite their having Islands to switch on your Islandwalk, you'll want to keep your Spreading Seas in postboard - it's a great answer for Inkmoth Nexus, which is otherwise one of the more annoying threats to deal with. Phyrexian mana removal spells are even better than usual here, as this deck typically won't even try to threaten your life total. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), hand disruption (Vendilion Clique), redirect effects (Spellskite), removal (Dismember, Gut Shot) tapdown effects (Tidebinder Mage). Side out: Slow haymakers (Master of Waves), value creatures (Benthic Biomancer).
Merfolk General Impression: Close matchup Synopsis: The true mirror hinges heavily on two things: which player (if any) has a Turn 1 Aether Vial, and which player (if any) draws Master of the Pearl Trident (as opposed to Lord of Atlantis, whose effect applies to both players' Merfolk). Harbinger of the Tides and Merfolk Trickster have very strong blowout potential by taking Lord effects off the table and messing up combat math, and Master of Waves can be swingy (amazing if Islandwalk is not a factor on the opposing side, slow otherwise). As usual in Vial deck matchups, countermagic is poor, though perhaps worth keeping if your sideboard is low on cards to bring in. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot), Vial hate (Mistcaller). Side out: Countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Mill (UBX) General Impression: Good matchup Synopsis: We have two key advantages in this matchup. First is that our reliance on basic lands and mono-colored manabase makes it very difficult for the opponent to cast Archive Traps, which buys us some time. Secondly, while they do run Ensnaring Bridge, it is not necessarily the best deck at emptying its hand and making it live. We can take advantage of that with some quick rushdown hands that provide too little time for the opponent to execute their gameplan while protecting themselves. Be judicious when playing nonbasic lands into an active Field of Ruin - you might be enabling an otherwise-dead Archive Trap or two. You should also be looking to stuff Crypt Incursion whenever possible, as that can set you too far behind to win the race. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), counterspells (Chalice of the Void, Dispel, Negate, Spell Pierce), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), redirect effects (Spellskite), tapdown effects (Tidebinder Mage). Side out: Value creatures (Benthic Biomancer), Seas effects (Spreading Seas).
Spirits (GUW) General Impression: Close matchup Synopsis: This deck is pretty close to ours in approach and abilities, with the differences being that their curve is a bit clunkier (which they make up for in part by playing more accelerants), and that their 3-color manabase gives them access to expanded tools (including the very powerful Collected Company) in exchange for taking more damage from their lands. In general, this matchup will favor whoever commits hard to the board first, but interaction on either end can lead to some big blowouts. As in other Vial matchups, countermagic is poor, but it still might be worth keeping in, as having a clean answer to Company can swing games. We have a slight edge because of our curve being a bit lower, but the fact that they run more accelerants makes it too close for us to take this matchup for granted. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), CoCo hate (Grafdigger's Cage, Mistcaller), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot). Side out: Countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Spirits (UW) General Impression: Good matchup Synopsis: This deck is about as close to being Merfolk without actually being Merfolk, but they have a few weaknesses that we can pick at: most 75s have no way of generating card advantage, their creatures are a bit less aggressively inclined (so their clock tends to be a half-step slower than ours), and they have very few answers to an opponent going wide on them (which often makes an unanswered Master of Waves game-winning). Things can get a little dicey if they have an Aether Vial and you don't, but you generally have the edge if the games go according to plan. Just remember to play through your Aether Vial whenever your opponent has 3 (or more) mana open or a Vial on 3, so as to avoid Spell Queller blowouts. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot), Vial hate (Mistcaller). Side out: Countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Amulet Titan General Impression: Bad matchup Synopsis: This matchup presents two major complications. First among these is that the deck is capable of some very fast hands with Primeval Titan + Amulet of Vigor, so not finding interaction in the first 2-3 turns of the game can mean that the game is over before you really get going. The second is that if you make your way to the midgame, this deck is capable of fetching some pretty problematic cards for us (Engineered Explosives and Walking Ballista) via either Trinket Mage or Tolaria West. Because of these factors, countermagic is the critical piece of interaction in order to ward off their haymakers. Cards like Merfolk Trickster can also buy you time against the Titan while clearing the way for your attackers to crash in. I have found that best results in the matchup come when the deck walks the aggro-control razor's edge. Because of this, hands with Aether Vial generally do better than ones without it. One final note is that if your opponent casts Summoner's Pact while not having the mana to pay for Spell Pierce and Primeval Titan, you should go ahead and cast the Pierce; it will cost you a card, but either force them into a suboptimal line or buy you 2 turns' worth of time. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Damping Sphere), countermagic (Ceremonious Rejection, Chalice of the Void, Dispel, Negate, Unified Will), hand disruption (Vendilion Clique), redirect effects (Spellskite), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage). Side out: Conditional bounce (Harbinger of the Tides), conditional land hate (Spreading Seas), slow haymakers (Master of Waves).
Scapeshift (RGX) General Impression: Close matchup Synopsis: The name of the game here is to kill them before they can attack with Primeval Titan or cast Scapeshift for lethal. There are several ways you can go about this. One of them is to curve out aggressively and counter stabilization tools like Anger of the Gods. Another is to play the aggro-control route and gradually commit to the board while countering ramp spells and payoffs alike. A harder-to-execute but more powerful third approach is to cut them off green mana with Spreading Seas, which can happen if they get a bit greedy fetching basic Mountains. One final note is that if your opponent casts Summoner's Pact while not having the mana to pay for Spell Pierce and Primeval Titan, you should go ahead and cast the Pierce; it will cost you a card, but either force them into a suboptimal line or buy you 2 turns' worth of time. Before the printing of Merfolk Trickster and the advent of maindecking counterspells like Deprive, I would have considered this matchup to be bad for Merfolk; however, these advances have gone a long way in giving us a fighting chance. Side in: Bounce (Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique), land hate (Sea's Claim, Tectonic Edge), tapdown effects (Tidebinder Mage). Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Tron (GX) General Impression: Close matchup Synopsis: While Tron is undeniably a powerful deck, and they have haymakers that can give us a ton of trouble (Oblivion Stone, Ugin, the Spirit Dragon, Walking Ballista, and Ulamog, the Ceaseless Hunger to a lesser extent), we are fortunate enough to have a fast clock to pressure them with and the maindeck ability to interact with Urza lands (Spreading Seas will strip a land of its types, turning off the "assemble 3 lands" effect until they find another copy). Depending on the contents of your hand, you'll be looking to either go pedal-to-the-metal and get them to 0 before the haymakers land, slap a Seas on their lands and take them to 0 before they can reassemble Tron, or play like a supersized Delver deck by getting early threats down and then holding up countermagic to ensure they reach the finish line. We also have access to a plethora of sideboard cards that perform well in the matchup. When taking the Seas approach, watch out for O-Stone and Nature's Claim interrupting your plans. Overall, this multiplicity of feasible approaches to winning the game gives us a bit of an edge, but Tron is too inherently powerful a strategy to take winning for granted. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Chalice of the Void, Dispel, Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique), land hate (Damping Sphere, Sea's Claim, Tectonic Edge). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), slow haymakers (Master of Waves).
Tron (UX) General Impression: Good matchup Synopsis: I find this to be one of our best matchups in the entire Modern format. Their principal ways of buying time to assemble the Urza lands (bounce and countermagic) are generally poor against an Aether Vial deck, and we feature a fast clock, disruption for their Urza lands, and unblockability to complicate matters further. While there are some haymakers you will want to interact with if possible (Oblivion Stone, Ugin, the Spirit Dragon, Walking Ballista), the best results in this matchup generally come from curving out and pressuring their life total quickly with a bit of disruption in the midgame to ensure you stay ahead on board. This is a matchup in which tempo matters much more than card advantage, so prioritize speed and aggressiveness. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Dispel, Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique), land hate (Damping Sphere, Tectonic Edge). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), slow haymakers (Master of Waves).
Devoted/Vizier Company (GWX) General Impression: Bad matchup Synopsis: Our struggles in this matchup largely stem from their speed (their fast hands can threaten to go off with infinite G plus the payoff of their choice as early as Turn 3) and our interaction package lining up somewhat awkwardly against a deck whose combo pieces are creatures (the permanent removal effects blue has access to are limited, to say the least). In order to win this matchup, you'll have to find the right mix of disruptive effects that actually impact the matchup, and use them to back up your early pressure. Tempo-type effects such as bounce and Merfolk Trickster should target the Devoted Druid above all, as the opponent has to untap with it in order for the infinite-mana combo it forms with Vizier of Remedies to truly be complete. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Mistcaller, Pithing Needle, Sorcerous Spyglass), countermagic (Dispel, Negate, Remand), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Cique), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage). Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Dredge General Impression: Good matchup Synopsis: Merfolk is one of the few decks that lines up well natively against the graveyard menace. We have disruptive creatures to buy time against their recursive threats, Spreading Seas can cut them off the RR they need for Conflagrate, shut down their Life from the Loam engine, or ward off Darkblast, and Master of Waves is a card they have few productive answers to. Furthermore, we have access to some good graveyard hate postboard. When to pull the trigger on a mass exile effect like Relic of Progenitus depends on the card that you're trying to beat. If you are trying to stop them from recurring creatures or draining you with a Creeping Chill, you can afford to be patient, as all of those abilities use the stack and can be responded to. That is not the case for Conflagrate, Darkblast, or Life from the Loam, and you should exile those on sight. Side in: Bounce (Echoing Truth), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), creature protection (Kira, Great Glass-Spinner). Side out: Conditional disruption (Merfolk Trickster), countermagic (Deprive), small value creatures (Benthic Biomancer).
Gifts Storm General Impression: Close matchup Synopsis: Game 1 against this opponent can be rough, as we have relatively few answers to their gameplan in the maindeck. You generally have to try and line up your maindeck counterspells with their cost reducers (Baral, Chief of Compliance and Goblin Electromancer) or Gifts Ungiven. Alternatively, Merfolk Trickster shuts off their cost-reducing effect, so an aggressive hand paired with some Tricksters on upkeep can stall them long enough for you to get there. Postboard, we have a significantly better shot at keeping them under wraps, as graveyard hate and extra countermagic hurt them quite a bit. Remember to bring in some bounce effects for Empty the Warrens, as that is the main way they will try to navigate around hate. My recommendation in this matchup is to not tap out on your turn past Turn 2 or so if you can avoid it - their deck is very explosive, and letting them do as they please for even one turn can spell doom. Side in: Bounce (Echoing Truth), combo hate (Damping Sphere), countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Clique), removal (Dismember). Side out: Conditional bounce (Harbinger of the Tides), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Living End (BRG) General Impression: Good matchup Synopsis: There are two approaches to be taken in this matchup. First among these is trying to deny them the ability to resolve their namesake spell. For that, you'll need a mix of countermagic and pressure to ensure that Living End never turns the tables on you (along with the occasional Spreading Seas to cut them off a color). A second approach (typically employed when one's hand is light on countermagic) is to mitigate the damage the spell will actually do. Tools often used for this purpose are deploying creatures at instant speed, as well as ways to deal with the fatties this deck dumps into the graveyard (either by exiling them as they hit the bin, or dealing with them once they're on the battlefield). Chief among the ones you must find an answer for is Archfiend of Ifnir, as that cycle effect is bad news for a go-wide deck. Overall, though, we feature the right mix of aggressive and interaction to give this deck fits. When lining up permission for postboard Living Ends, bear in mind that Ricochet Trap may be lurking. Side in: Bounce (Venser, Shaper Savant), countermagic (Chalice of the Void,Negate, Remand, Spell Pierce), graveyard hate (Mistcaller, Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), small value creatures (Benthic Biomancer).
Azorius Control General Impression: Good matchup Synopsis: This matchup sometimes gives newer Merfolk players a bit of trouble, but I believe we have a notable edge once you learn the ropes. Generally, you're trying to keep value engines (such as the planeswalkers, Cryptic Command, Snapcaster Mage, Search for Azcanta, and sweepers like Supreme Verdict and Terminus) from running you out of resources. You can accomplish this with countermagic of your own, by killing the 'walkers as soon as they hit the field, or by leveraging manlands for offense to minimize the effect of sweepers. Unlike in most U-centric matchups, Spreading Seas is worth keeping around postboard, as many of the ways this deck is trying to beat you revolve around lands. Don't waste precious resources dealing with things our deck is inherently built to battle through (such as Path to Exile on non-critical creatures or a Timely Reinforcements you can islandwalk around), and you will do well. Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster).
Blue Moon General Impression: Good matchup Synopsis: This deck comes in two major flavors: the combo varieties use things like Madcap Experiment into Platinum Emperion, Deceiver Exarch plus Kiki-Jiki, Mirror Breaker, and Through the Breach into Emrakul, the Aeons Torn to win games, whereas the "pure control" varieties focus harder on card advantage and try to win eventually via Snapcaster Mage, Thing in the Ice, Vendilion Clique, and occasionally Pia and Kiran Nalaar. What version you are facing influences whether cards such as Merfolk Trickster (which is pretty good against the combo versions) should make the postboard cut. Regardless of what version you're facing, the general approach is similar: deploy aggressively early, weather the initial removal spells, and try to leverage your interaction to win races in the mid-to-lategame. Master of Waves is a card this deck struggles mightily to answer, so centering your gameplan around sticking him with a decent amount of devotion is a good way to win games. This deck generally relies heavily on countermagic and land hate to slow its opponents down, which does little against a deck with lots of basic Islands and Aether Vial. They also don't feature enough spot removal to put a major dent in your plan. You have a pretty convincing edge in this matchup. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Jeskai Control General Impression: Close matchup Synopsis: While Merfolk generally doesn't mind facing a bit of spot removal, this deck has enough of it to actually pose a challenge to your gameplan. To counteract that, you need to break from the classic "don't over-commit" control gameplan a bit and get on the board aggressively. Being able to get your guys out of Bolt range (while not easy) is a major boon, as it invalidates a big chunk of their spot removal. This tactic is less likely to get punished than against other control opponents, as they tend to run fewer sweepers, especially in Game 1. As usual against a U-based deck, play through your Aether Vial to avoid countermagic and sorcery-speed effects, counter planeswalkers and other value engines when you can, and beware the Snapcaster Mage-into-removal line wiping your board. Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Pyro Prison General Impression: Close matchup Synopsis: This matchup revolves around Ensnaring Bridge - in Game 1, you need to counter it or kill your opponent before they find it and empty their hand enough to lock out your offense. Postboard, you bring in your answers and can thus answer an active Bridge lock. Other annoying cards to watch for are Chandra, Torch of Defiance and Anger of the Gods. The Rabblemaster plan (Goblin Rabblemaster and Legion Warboss) is typically not that much of a threat, since Merfolk is readily capable of putting bodies in front of the tokens, or trade with the token generators themselves. As long as you can keep the Bridge angle under control, you should win. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Sultai Reclamation Control General Impression: Good matchup Synopsis: The main thing to watch out for out of this matchup is that the deck is primarily composed of instants, and cards like Consume the Meek can be a beating if they catch you unprepared. However, this deck is generally a bit light on removal density, instead relying on Wilderness Reclamation to double up its turn-by-turn mana production and on Mystical Teachings to find whatever it may need. Disrupt that engine, and you will find that the deck is often too slow to threaten you. Alternatively, put together a fast aggro start, and they may take too long to get set up. Postboard, you can bring in some more disruption for their gameplan to keep things running smoothly. Because this deck is mostly focused on spell-slinging, most of your interaction points will be on the stack or in the graveyard. Regardless, most Merfolk decks should have a comfortable edge in this matchup. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Grafdigger's Cage, Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Whir Prison General Impression: Bad matchup Synopsis: This deck is able to get an Ensnaring Bridge quickly, reliably, and then protect it in a variety of ways, which makes it a pretty challenging matchup for us. The key to getting there in this matchup is to start aggressively - you're going to want to curve out in the first 2-3 turns of the game, and either threaten a Turn 4 kill or have some countermagic to hold up in the midgame (and ideally, you want to have both those things going on). Chalice of the Void on 2 turns off most of our deck, and Engineered Explosives on 2 blows most of it up, so those are cards you may be forced to interact with in order to win. If you do counter the Bridge, bear in mind that they feature tools to either get another copy (Inventors' Fair, Whir of Invention) or to fish it out of the graveyard (Academy Ruins), so don't take too long to finish the game, or they will re-establish their lock. Not a good matchup, but certain hands feature the right combination of disruption and pressure to win. Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Abzan General Impression: Close matchup Synopsis: While most BGX decks are similar to each other from our perspective, this one has one particularity to note in that it features a go-wide angle in Lingering Souls. These tokens are rarely much of a threat in their own right, but they can buy your opponent time as blockers and generally muck up the battlefield if you don't happen to have a Seas effect. Furthermore, their reliance on W and B for their removal means you can't quite lean as heavily on Master of Waves as you would in other midrange matchups. Apart from that, the standard advice applies: fight through their discard and removal by presenting a constant stream of threats, don't mulligan if you can avoid it, mess with their manabase using Spreading Seas, pressure their life total hard if they have an active Dark Confidant, and try to clear any Liliana as soon as she hits the battlefiddddeld. Handling their other threats with bounce, Trickster, or postboard graveyard hate also comes highly recommended. Side in: Bounce (Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage). Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation).
Eldrazi Stompy (mono-C) General Impression: Close matchup Synopsis: This matchup often comes down to who can sustain their pressure from the early game to the midgame. While Eldrazi tends to be a fast starter thanks to being willing to dig for double-mana Eldrazi Temples and the like using Serum Powder or aggressive mulligans, all that tearing through the deck can sometimes leave your opponent light on gas. That means that if you can weather the initial wave of Thought-Knot Seers and Reality Smashers that are popping out ahead of schedule by either disrupting them, getting on board faster than them, or slowing them back down with Spreading Seas, you'll be in a great spot to flip the script on your opponent. I recommend trading off or disrupting Eldrazi Mimic early (as it can otherwise have an outsize impact for what is effectively a 1-drop in many Eldrazi hands) and not trading with Eternal Scourge or Matter Reshaper if at all possible. Last but not least, watch out for Chalice of the Void or postboard Ratchet Bombs on 2, especially if you don't have an Aether Vial. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Remand), hand disruption (Vendilion Clique), removal (Dismember). Side out: Countermagic (Deprive, Force of Negation), value creatures (Benthic Biomancer).
Grixis Shadow General Impression: Good matchup Synopsis: The more controlling of the Shadow variants, this deck has two major weaknesses to our deck: it relies heavily on U (so it switches on islandwalk for us without any effort required), and it hacks away at its own life total to leverage some of its powerful cards, such as Death's Shadow (which means you have to sneak through significantly less damage to win). It also has a postboard weakness in that graveyard hate is quite good against it, as the graveyard fuels both Gurmag Angler and Snapcaster Mage. To win this matchup, you generally want to put pressure on them to develop their board (which usually involves them damaging themselves) while simultaneously having to deal with removing your threats. Next, you can either skip past their blockers with islandwalking hordes, or disrupt their big individual threats with the likes of Harbinger of the Tides and Merfolk Trickster. You'll generally have to weather some discard spells and removal to pull this off, but that's something Merfolk is well-equipped to do. Last but not least, beware the Temur Battle Rage, as that is one of the main ways this deck can steal games from you and your blockers. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), graveyard (Relic of Progenitus), hand disruption (Vendilion Clique), land hate (Sea's Claim), removal (Dismember), removal protection (Kira, Great Glass-Spinner). Side out: Accelerants (Aether Vial), countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Jund General Impression: Close matchup Synopsis: The most historically common of the BGX decks, Jund is a matchup where inexperienced Merfolk players sometimes struggle, but seasoned pilots have a markedly easier time with. The key to it is to keep them on the back foot with a constant stream of threats that they must answer, and thus keeping them from mounting an offense of their own. Because of this, Silvergill Adept is often your best card in the matchup, as it is a card they must answer that gets you another card. That said, because of Jund's reliance on R for its removal spells, Master of Waves is also quite good. Mulliganing is also something I only recommend you do if your hand is truly non-functional, as you need as many resources as you can scrounge up at your disposal. Disrupting their attempts to start an offense also comes highly recommended, so lining up Merfolk Trickster with Tarmogoyf, putting a lid on Raging Ravine with Spreading Seas, walling Bloodbraid Elf with blockers, resetting Scavenging Oozes with bounce, or killing any Liliana planeswalker on sight are all very good things to be doing. Postboard, you should also bring in graveyard hate to aid you in keep their threats manageable. Lastly, if faced with an active Dark Confidant without a reliable means to take it off the battlefield, commit hard to pressuring their life total - they do some amount of damage to themselves with fetches, shocks, and Thoughtseize, so turning their life total against them can help you walk away with wins where your opponent is way ahead on cards. Side in: Bounce (Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage). Side out: Accelerants (Aether Vial), condition bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation).
Mardu Pyromancer General Impression: Close matchup Synopsis: This midrange deck's particularities are that it has a go-wide threat dimension composed of Young Pyromancer tokens and Spirits from Lingering Souls, and that it can generate big chunks of card advantage by slowing the game to a standstill then slamming Bedlam Revelers to refill its hand. Because of these angles of attack, postboard graveyard hate plays a big role in the matchup. Because this deck leans heavily on R for both threats and removal, Master of Waves is an absolute beating, and can sometimes win games more or less on its own. Apart from that, your standard attrition gameplan applies: don't mulligan if you can avoid it, present a constant stream of threats, try to disrupt their threats whenever you can, and prioritize cards that let you do those things while replacing themselves (such as Silvergill Adept and Spreading Seas). Side in: Bounce (Echoing Truth, Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage). Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive).
Ponza (RGX) General Impression: Good matchup Synopsis: One of our best matchups in Modern, this deck attacks an axis we are well-prepared to defend. Blood Moon and Stone Rain don't do much against a deck with lots of basic lands and Aether Vial, and their mostly R-based threats and removal line up pretty poorly against a Master of Waves. Hitting a land with Utopia Sprawl on it with Spreading Seas is also a nasty blowout, as the Utopia Sprawl will no longer be legally enchanting that land and will thus fall off. Your goal here should be to start pumping out threats, disrupt their mana acceleration (or answer their threats with countermagic, bounce, or tapdown effects), and beat them down before they can recover. My experience is that Merfolk is exceedingly good at executing this gameplan against Ponza, and thus wins the matchup quite often. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Remand), hand disruption (Vendilion Clique), land hate (Sea's Claim), tapdown effects (Tidebinder Mage). Side out: Conditional bounce (Harbinger of the Tides), value creatures (Benthic Biomancer).
The Rock (BG) General Impression: Close matchup Synopsis: A relative newcomer to the BGX lineup, this one features Field of Ruins to attack your Mutavaults, a less painful manabase to mitigate the bad side of Dark Confidant, and Kalitas, Traitor of Ghet as a nasty top-end threat. A strategy I've sometimes employed to good effect is to cut them off colors by relying on basic lands to cast my spells (thus stranding the Fields) and slapping Spreading Seas on their remaining lands (especially if they are dual lands). Directing your creature interaction toward Kalitas will also help keep him under wraps. Apart from this, the standard BGX advice applies: fight through their discard and removal by presenting a constant stream of threats, don't mulligan if you can avoid it, pressure their life total hard if they have an active Dark Confidant, and try to clear any Liliana as soon as she hits the battlefield. Handling Scavenging Ooze and Tarmogoyf with bounce, Trickster, or postboard graveyard hate also comes highly recommended. Side in: Bounce (Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage). Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation).
Traverse Shadow General Impression: Good matchup Synopsis: The more aggressive of the Shadow variants, this deck still hacks away too hard at its own life total to have a good Merfolk matchup. It also has little use for U, so Spreading Seas can often be quite painful. Still, this deck can pose a threat by powering out undercosted beaters in Death's Shadow and Tarmogoyf, so have your creature disruption at the ready. Patience is key in this matchup - let them damage themselves to enable their gameplan while you develop your board, and then proceed to disrupting them while simultaneously upping the pressure. Postboard graveyard hate hits this deck very hard, so it comes highly recommended. As long as you can keep yourself from being overwhelmed by undercosted fatties or having a game snatched from under you by a Temur Battle Rage, you are a strong favorite to win. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), graveyard (Relic of Progenitus), hand disruption (Vendilion Clique), land hate (Sea's Claim), removal protection (Kira, Great Glass-Spinner). Side out: Accelerants (Aether Vial), countermagic (Deprive, Force of Negation).
Fringe Decks:
Delver (URX) General Impression: Good matchup Synopsis: There are two basic types of Delver decks in Modern. One variety is the spell-heavy decks that add B or G to the mix and pair Delver of Secrets with complementary threats such as Tarmogoyf and Hooting Mandrills or Gurmag Angler and Tasigur, the Golden Fang. The other is a more tribal-style strategy that employs the likes of Vendilion Clique and Nimble Obstructionist as additional threats. Our approach to both versions is similar - they tend to have quite a bit of spot removal and Snapcaster Mages to run it back, so you'll need to weather that and interact with their threats as you take over the board and chip down their life total. Harbinger of the Tides tends to be especially valuable here, as many of their threats require setup. Lords are also quite strong, as the nature of these decks' construction means islandwalk is pretty much always on. Aether Vial also helps quite a bit here, as it can help you deploy faster and allows you to dodge countermagic. Lastly, most of these decks struggle to interact with Master of Waves, so he's a great haymaker to work your way up to. As long as you can keep them on the back foot (and most of the time, you can), you have a marked edge. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Remand), flyers (Kira, Great Glass-Spinner, Vendilion Clique), graveyard hate (Relic of Progenitus), removal (Dismember, Gut Shot). Side out: Seas effects (Spreading Seas).
Eldrazi (RGC) General Impression: Close matchup Synopsis: This matchup is usually a good old-fashioned race: can your Lord-stacking get to the finish line before their large, hasty threats? Because of this goal, you generally want to see a bunch of Lords, and supplement them with a bit of disruption. Your creatures are usually cheaper, so try to get boots on the ground first and establish a life lead. They play a decent amount of spot removal, so be careful about getting blown out in combat by something like a Bolt on your Lord. Lastly, be careful about running out a Master of Waves without countermagic backup or a second copy already in play - Eldrazi Obligator's additional effect is colorless in nature, and they can use it to steal your Master and kill your tokens. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Remand), hand disruption (Vendilion Clique), land hate (Sea's Claim, Tectonic Edge), removal (Dismember). Side out: Value creatures (Benthic Biomancer).
Eternal Command General Impression: Good matchup Synopsis: This deck's primary goal is to set up an Eternal Witness + Aether Vial + Cryptic Command loop to counter the first spell an opponent plays every turn. Needless to say, this takes a bit too long to truly be effective against Merfolk, and the resulting effect is not that strong against us either. Their plan B usually involves a graveyard-based value game involving removal spells, Scavenging Ooze, Snapcaster Mage, and Tarmogoyf. Because they gift you islandwalk by nature of their manabase and our ability to bring in postboard graveyard hate, this plan is also unlikely to stop you. Get on the battlefield early, pressure their life total, and save some disruption for their any loop pieces or attempts to stabilize, and you'll do well. Side in: Countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique), removal (Dismember). Side out: Seas effects (Spreading Seas).
Hatebears (WG) General Impression: Good matchup Synopsis: This deck is looking to punish certain types of game actions, such as countermagic, discard, noncreature spell-spamming, and searching one's library for cards, while pressuring them with creatures such as Thalia, Guardian of Thraben and Leonin Arbiter. You'll note that none of those effects are all that common in Merfolk, and thanks to Lord-stacking, our creatures tend to be larger. Because of this, the matchup tends to be pretty favorable. Things you do want to watch out for are big creatures like Wilt-Leaf Liege (which allows them to do some Lord-stacking of their own) and Loxodon Smiter coming down ahead of schedule thanks to mana dorks like Noble Hierarch. Put boots on the ground in the early game, save some disruption (especially board disruption) for their big guys, and you'll do fine. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot). Side out: Countermagic (Deprive, Force of Negation), small value creatures (Benthic Biomancer).
Soul Sisters General Impression: Close matchup Synopsis: There is some variation in the exact decklists for this archetype: some are mono-W decks that lean on the likes of Honor of the Pure, Ajani's Pridemate, Squadron Hawk, and Spectral Procession to close out games, while others splash R for Norin the Wary and lean heavily on Human synergies via Champion of the Parish and Thalia's Lieutenant. Regardless of what version you face, the gameplan is the same: you want to build up a bigger board state than theirs, then use Seas effects to punch through their defenses and hack through their lifegain while disruptive creatures keep their threats off you. Bear in mind that the Sisters themselves (Soul Warden, Soul's Attendant, and occasionally Auriok Champion) can also attack and block, so keep blockers back to prevent chip damage and gobble them up with combat tricks if you are presented with an opportunity to do so. Side in: Bounce (Echoing Truth), countermagic (Chalice of the Void), removal (Dismember, Gut Shot). Side out: Go-wide haymakers (Master of Waves), countermagic (Force of Negation), small value creatures (Benthic Biomancer).
Zoo (Bushwhacker) General Impression: Close matchup Synopsis: This is a pretty fast all-in aggro deck, so you'll need some of Merfolk's defensive resources at your disposal in the early game to stem the early tide of creatures, especially if they get haste from a Reckless Bushwhacker. You should also watch out for Atarka's Command messing up your combat math. Once you stem the offensive tide with Harbinger of the Tides and/or Merfolk Trickster, Master of Waves is often the best way to flip the script on them. Alternatively, they have a pretty color-intensive deck combined with a fragile manabase, so Spreading Seas can sometimes pull a lot of weight here. The general gist of the matchup is that the longer the game goes, the better it is for you. Side in: Bounce (Echoing Truth), countermagic (Chalice of the Void, Dispel), land hate (Sea's Claim), redirect effects (Spellskite), tapdown effects (Tidebinder Mage). Side out: Countermagic (Deprive, Force of Negation), small value creatures (Benthic Biomancer).
Zoo (Classic) General Impression: Good matchup Synopsis: This deck is similar to ours in that it seeks to back up mid-size creatures with a bit of disruption, but they present several weaknesses in the head-to-head contest in a painful manabase that doesn't have much use for U (so Spreading Seas is strong in the matchup), some sensitivity to graveyard hate (via Knight of the Reliquary, Scavenging Ooze, and Tarmogoyf), and a clunkier curve with lots of 3-drops and only a nominal amount of mana acceleration. Because of this, we generally get our pressure going first, can cut them off colors while enabling our unblockability, and can disrupt them while further developing our battlefield. We can even outmuscle them, if our draw has enough Lords. They do run a fair amount of spot removal (especially postboard), so be careful when attacking into their creatures. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), flyers (Kira, Great Glass-Spinner, Vendilion Clique), land hate (Sea's Claim), removal (Dismember), tapdown effects (Tidebinder Mage). Side out: Small value creatures (Benthic Biomancer).
Devotion (GX) General Impression: Good matchup Synopsis: This deck's goal is to combine effects that untap lands on creatures (namely Arbor Elf) and planeswalkers (Garruk Wildspeaker) with enchantments such as Utopia Sprawl or with Nykthos, Shrine to Nyx to make tons of mana and ramp out powerful expensive spells. Your primary goal should be to interact with that gameplan as much as possible while also pressuring their life total. Fortunately, you have many tools to help you accomplish this goal. Spreading Seas deals with Utopia Sprawl while also drawing you a card and enabling islandwalk. Merfolk Trickster and Harbinger of the Tides can help you slow down their creature-based ramp, and your aggro game can help get Garruk off the table as soon as he hits. Furthermore, some of the haymakers the deck puts out just aren't that scary to Merfolk - the likes of Hornet Queen can be circumvented via islandwalk, for example. As long as you're getting a healthy mix of disruption and pressure, this is a matchup you should win. Side in: Bounce (Echoing Truth, Hibernation, Venser, Shaper Savant), countermagic (Remand), hand disruption (Vendilion Clique), land hate (Sea's Claim), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage). Side out: Slow haymakers (Master of Waves).
Scapeshift (UGX) General Impression: Good matchup Synopsis: These decks are usually running what amounts to a ramp-control gameplan until they have enough lands to threaten an instant kill with Scapeshift. As such, you have two avenues to victory - one is to threaten them with a resilient aggro game and ignore the ramp aspect (because you're hoping to kill them before they have Scapeshift mana); the other is to interact with them as best you can and hope incidental pressure carries the day. Either is effective (though I have found the aggressive one to be a bit more so), and which one you opt for usually depends on your draw. Fortunately for us, the fact that we don't take damage from our manabase effectively buys us an extra turn against their primary win condition, which usually gives us the time we need to scratch together enough damage to cross the finish line first. Watch out for sweepers (especially if the opponent is on the 4/5-color Bring to Light variant) and postboard backup plans like Madcap Experiment into Platinum Emperion, and you should be fine. Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique), land hate (Tectonic Edge). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Cheeri0s General Impression: Close matchup Synopsis: This matchup hinges entirely on wehther you can scratch together enough interaction to allow your beatdown plan to finish the game. Their win condition, while inconsistent, is blazing fast, so you must be prepared to interact in order to win. Going for their card draw engines (Puresteel Paladin and Sram, Master Edificer) or locking them out of casting 0-drops with Chalice are the safest routes, but occasionally countering the likes of Retract will cause them to stall out. As you do that, build up your board, pressure them aggressively, and hopefully it's enough. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), hand disruption (Vendilion Clique), removal (Dismember). Side out: Conditional bounce (Harbinger of the Tides), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Jeskai Ascendancy General Impression: Close matchup Synopsis: Your goal here is typically to catch the namesake Jeskai Ascendancy enchantment on the stack, and then beat your opponent to death with your Merfolk while they dig for a new one. Alternatively, interacting with their win conditions (usually a Fatestitcher, though some versions also play G for access to mana-producing creatures instead) can also buy you some time. The key thing to keep in mind is that you must develop your gameplan quickly: this deck is mostly composed of cantrips, so the deck will find what it needs if given enough time. That said, this also means that they usually cannot spare much deck space to interacting with their opponents, so the straightforward rushdown is pretty effective against them. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Spell Pierce), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot). Side out: Conditional bounce (Harbinger of the Tides), Seas effects (Spreading Seas), slow haymakers (Master of Waves)
Restore Balance General Impression: Close matchup Synopsis: The effects of the namesake spell resolving are typically devastating for a creature deck like Merfolk, so your gameplan revolves areound making sure it doesn't. With that said, don't neglect your ability to apply pressure; they will eventually force a way past their defenses if you give them enough time. Interacting with the Borderposts that they use for mana in lieu of lands is highly recommended. Lastly, don't lose sight of the fact that most iterations of this deck can threaten the combo at instant speed through either Electrodominance and Violent Outburst, so try not to tap out in the midgame if you can avoid it. This matchup clearly gets easier with the more permission you run. Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Saheeli/Copycat Combo General Impression: Good matchup Synopsis: There are two major iterations of this deck. One of them uses a Jeskai midrange shell, with notable amounts of spot removal and cantrips; the other is a G-based 4-color deck that tries to assemble the necessary mana a bit faster with the likes of Birds of Paradise and Lotus Cobra, then generates consistency with tutor effects such as Eldritch Evolution. Either variant brings the threat of a value midrange game (featuring lots of enters-the-battlefield effects to rebuy with Felidar Guardian) while the combo is being assembled, but both of them usually grant you islandwalk in the process of casting their spells, which is a nice boon. The combo itself is easy enough for us to interact with; deal with either the Felidar or with Saheeli Rai, and the music stops. This combination of circumstances make this a matchup Merfolk is well-suited to winning. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand), hand disruption (Vendilion Clique), removal (Dismember), tutor hate (Grafdigger's Cage). Side out: Conditional bounce (Harbinger of the Tides), Seas efects (Spreading Seas), slow haymakers (Master of Waves).
Thopter Sword (UBX) General Impression: Close matchup Synopsis: Unlike most creature decks, Merfolk is able to slip through a mass of Thopter tokens should the Sword of the Meek + Thopter Foundry combo get assembled (especially since this deck will give you the islandwalk for free, as most of its non-artifact spells are U-based), so that occurrence is not game over for us. This gives us game in the matchup that other decks cannot boast. However, your goal should be to drop your opponent before they manage to assemble these pieces. Ensnaring Bridge is usually present in these decks, so plan your sideboarding accordingly. Interact with the Foundry on the stack if you can - hand disruption and Spellskite will make it significantly more difficult once it's on the table. Other than that, proritize pressure and try to get them low before they assemble the combo, such that they need something other than the combo to bail them out. Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Turns (UX) General Impression: Close matchup Synopsis: While this deck has access to some annoying ways to punch through your defenses in Exhaustion and Gigadrowse, the plan to develop your board early and hold up countermagic as you clock them is something this deck is quite weak to. Deal with their extra draw engines (Dictate of Kruphix, Jace, the Mind Sculptor, and occasionally Howling Mine or Ancestral Vision) if you get a chance - this makes it much harder for them to find the resources to attempt to go off, and to sustain the chain once they being to do so. Prioritize hands that have fast starts - your goal should be to threaten lethal by the time they've begun to set up, or at the very least to have a counterspell and a clock. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Vannifar "Pod" Combo General Impression: Close matchup Synopsis: While creature-based combo decks typically give Merfolk a bit of trouble, this one throws us a few bones in that its main combo piece costs 4 mana (which gives us enough time to set up countermagic), requires U to be cast (which means we sometimes get islandwalk for free), and that our disruptive Merfolk are effective speedbumps against it (an instant-speed Harbinger of the Tides or a Merfolk Trickster will both buy you a turn). With that in mind, you have a reasonable chance of putting together the mix of disruption and pressure you need to win this game. Bear in mind that Prime Speaker Vannifar is there to fetch the winning combo (typically Kiki-Jiki, Mirror Breaker combined with some way to untap it), not be the win condition herself; if the game goes long enough, they can draw into the combo naturally. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Negate), graveyard hate (Grafdigger's Cage, Relic of Progenitus), hand disruption (Vendilion Clique), removal (Dismember), tapdown effects (Tidebinder Mage). Side out: Seas effects (Spreading Seas), slow haymakers (Master of Waves).
8-Rack General Impression: Close matchup Synopsis: While this is a discard-based attrition deck, Aether Vial is actually pretty handy here, as they usually play some amount of land destruction, sometimes have sorcery-speed sweepers, and extra copies can be held to weaken the effects of Wrench Mind. You'll also want to take the draw in any postboard games where you get the choice in the matter; resources are of paramount importance in the matchup. Generally, you want to try and establish a strong board presence early, and get stuff out of your hand before it gets picked off by targeted discard. Once The Rack and/or Shrieking Affliction are on the table, you should reverse course and attempt to hoard as many cards in your hand as possible, unless casting those cards would allow you to outrace their effects or they have a recurring discard outlet, such as Liliana of the Veil or Raven's Crime. Lastly, this deck sometimes packs Ensnaring Bridge, so plan accordingly. Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Emeria Titan General Impression: Good matchup Synopsis: This is a slow value deck that grants you islandwalk for free and is somewhat light on interaction, all of which combines to make it easy prey for us. Get Lords on the table, protect them with countermagic, and rush them down without fear. If you do, their deck philosophy of buying time with blockers and lifegain until they can run their opponent out of resources is unlikely to work on you. Watch out for the occasional Supreme Verdict, try to counter their Sun Titans, bring in your postboard graveyard hate, and keep your Seas postboard (evasion is paramount, and shutting off Emeria, the Sky Ruin can be useful in longer games). Side in: Bounce (Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Esper Control General Impression: Good matchup Synopsis: While this control deck has a deep suite of spot removal and card advantage tools, it is very slow to turn the corner, which affords you lots of time to mount an offense, recover from disruption, and keep chipping away. They will usually feature some amount of sweepers, so be careful not to over-extend into them. One way to do that is to play through your Aether Vial, which has the additional benefit of avoiding their countermagic. Countering or otherwize limiting card advantage engines such as Teferi, Hero of Dominaria is one of the best ways to deal with these types of opponents. As long as you stay disciplined and keep the gas flowing, this should be a matchup you win quite often. Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Grixis Control General Impression: Good matchup Synopsis: While this is a control deck, it mostly relies on spot removal to hold the fort in the early game, and thus you can be aggressive with your creature deployment and force them to deal with lots of threats at once. Lord-stacking is quite important here, as it helps you get out of range of Lightning Bolt and Kolaghan's Command. Despite being vulnerable to that card, Aether Vial is very handy here, as it helps you deploy more quickly and avoid their countermagic. Graveyard hate is especially effective here, as many of their threats and value mechanisms rely on it. Our combination of unblockable pressure and disruption is typically pretty hard to overcome, so Merfolk enjoys a marked edge. Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Lantern Control General Impression: Bad matchup Synopsis: Arguably the worst matchup for Modern Merfolk. Their ability to quickly slap down Ensnaring Bridge and dump its hand makes it very challenging for us to mount an offense, and it can pick off our limited ways to deal with said Bridge with discard spells and mill effects such as Codex Shredder combined with Lantern of Insight. To top it off, the deck has Ancient Stirrings, Inventors' Fair, and Whir of Invention to help it dig for what it needs. Your best chance here is to catch the Bridge coming in and clock them before they can find another, Chalice them out of their 1-drops and eventually find an answer for Bridge, or to knock their life total low before they apply the lock and sneak through the final points after dealing with the Bridge for a turn. Unfortunately, my experience is that this is highly unlikely. Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Chalice of the Void, Negate, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Skred Red General Impression: Good matchup Synopsis: This deck has a good amount of removal to slow you down, but its combination of vulnerability to countermagic (due to its reliance on big, expensive threats) and its general inability to deal with a resolved Master of Waves make us a pretty convincing favorite. Getting your threats out of range of Anger of the Gods and Lightning Bolt range is also a massive boon, though you should take care to not get blown out by a souped-up Skred. Strategy-wise, your goal is to exert constant pressure on your opponents, forcing them to expend resources holding you off. When a threat hits the table, you should attack it if it's a planeswalker, or interact with it if it's a creature. If you cannot interact with it, redouble your efforts to protect your own creatures - chances are that you can win a race, if it comes to that. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique), removal (Dismember). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Sun & Moon General Impression: Good matchup Synopsis: While this is a prison deck, some of its lock pieces (Blood Moon and Chalice of the Void on 1) are pretty ineffective against us, which combines with a clunky manabase to give us a marked edge in the matchup. Kill their planeswalkers on sight, play around sweepers by deploying creatures at instant speed with Aether Vial, and keep chipping away at their life total, and your opponent will likely capitulate. They may feature Ensnaring Bridge, so be sure to bring in your postboard answers to that card. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique). Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas)
Sultai General Impression: Good matchup Synopsis: This deck is similar in configuration to other BGX midrange decks, but presents us with one major advantage: its usage of U means they provide us with Islands, often rendering their creatures unable to block. Because of this, the matchup has a markedly more positive spin than its cousins. Apart from this, the standard BGX advice applies: fight through their discard and removal by presenting a constant stream of threats, don't mulligan if you can avoid it, pressure their life total hard if they have an active Dark Confidant, and try to clear any Liliana as soon as she hits the battlefield. Handling Scavenging Ooze and Tarmogoyf with bounce, Trickster, or postboard graveyard hate also comes highly recommended. Side in: Bounce (Venser, Shaper Savant), graveyard hate (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage). Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Tokens (WBX) General Impression: Good matchup Synopsis: The key to winning this matchup usually involves assembling the combination of islandwalk and Spreading Seas. Your task is to put that together through their spot removal and discard, and to do so quickly enough to outrace their flyers and pump effects. Fortunately, they're usually a pretty slow starter, so you'll have quite a bit of time to get things going and beat them to the spot. Alternatively, you can set up for a big Master of Waves, and beat them at their own go-wide game. An important part of the matchup is to address their value engines - Bitterblossom is usually not the biggest deal, but any planeswalker should be countered or taken down as soon as possible. Postboard, mass bounce effects tend to be crippling, as they are often one-sided boardwipes. This is a matchup in which you enjoy a significant speed advantage. Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus). Side out: Accelerants (Aether Vial), creature interaction (Harbinger of the Tides, Merfolk Trickster).
These cards are the core of the Modern Merfolk deck:
Aether Vial – This is our tempo anchor. It gives you the ability to spit out creatures faster than you could otherwise cast them, and adds to your interaction ability by flashing your creatures in response to your opponent’s spells or even as a combat trick. They can be a bit of dead topdeck (which is why they tend to come out against decks with an attrition gameplan), but in general it is one of your most important cards. In fact, it's so important, that it gets its own section, as described below.
Force of Negation – An absolutely incredible spell for Merfolk. This lets you both develop your board and protect yourself from whatever your opponent has going on in the early game, and can quite easily be cast using its normal mana cost in the mid-to-late game. Because the vast majority of cards in this deck are blue, you'll rarely be lacking for fodder to feed it, and its tempo boost can be the difference between a win and a loss. I consider it an essential part of the Modern Merfolk toolbox.
Island – They help you cast your dudes and your spells. Boring, but effective.
Lord of Atlantis – One of the major reasons to play this deck. Global pump and evasion along with a 2/2 body are a heck of a deal for UU, and it gets only scarier in multiples. Just be careful when playing the mirror – he pumps your opponent’s guys, too.
Mutavault – This useful little land gives us another body to project all of our tribal buffs onto (including that of Master of Waves), and it has the benefits of being cheap to activate, colorless (so it can dodge effects meant for U creatures, such as protection), and that it dodges sorcery-speed or nonland permanent removal spells. Another note is that you can sandbag its activation during the combat phase to try and dodge effects such as Cryptic Command, but beware of what you say when entering combat - otherwise, you may find yourself in situations like this one. The fact that it doesn't produce U can sometimes be a bit problematic, but it's a problem we're well-equipped to deal with thanks to Aether Vial. A staple in this deck, and for good reason.
Silvergill Adept – This guy gives us a nice body to project our pump effects on as well as another card. His drawback rarely comes up given our deck’s typical creature count, and it keeps the engine running smoothly. Along with the Lords, this card's existence is what makes Merfolk a thing.
Spreading Seas – One of our sneaky-good tempo pieces, this card fulfills multiple roles in our deck. It grants our creatures evasion when one of our Lords is on the table, it can disrupt your opponent’s mana base, and it replaces itself to boot. A bit hit-or-miss against most decks that already run U, but very potent in general.
Preferred Card Choices:
This section will focus on cards that have been proven to be successful complements to the Merfolk core cards shown above. If it's not on this list, it's likely a budget alternative (see the section below), or it's just not that good in Merfolk. I'm also marking the choices with a tag that should clarify whether a card is generally thought to be mainboard or sideboard-playable (and in some cases, both).
Artifacts:
Chalice of the Void – This is a very potent tool to bring in against opponents who rely heavily on 0-drops (such as Affinity, Cheeri0s, or Living End) or 1-drops (Bogles, Burn, Death's Shadow, Elves, Infect, GX Tron, and Phoenix). It can be a bit clunky on the draw, and it's not the greatest topdeck, but its early game shutdown potential makes it worth running. Whether it forms part of your mainboard or your sideboard depends on the expected metagame. Mainboard or Sideboard
Damping Sphere – If you expect to face big mana decks like Amulet and Tron, pure spell-spam decks like Phoenix and Storm, or any other deck looking to slam multiple spells in a turn or cheat on mana production, this will be a very potent tool in your sideboard arsenal. While it won't lock your opponent out of the game altogether, it will slow them down significantly, and Vial ensures it likely will not do the same to us. Sideboard
Grafdigger's Cage – This handy little artifact puts a damper on everything from conventional graveyard reanimation decks to Snapcaster Mage triggers to cards like Chord of Calling and Collected Company. Not truly applicable enough to be featured in the mainboard, but it's a potent sideboard bullet that can really make some matchups (notably Company decks, reanimator decks, and any combo deck relying on tutors or the graveyard) less troublesome. Sideboard
Pithing Needle – While this card requires some knowledge of the inner workings of your opponent's deck to be of optimal use, it can be a cheap answer to a lot of problematic permanents that doesn't interfere with your curve. At its best when brought in from the sideboard once you know what you're playing against. Sideboard
Relic of Progenitus – Probably the best piece of graveyard hate for Merfolk. It’s cheap to cast, and it can either whittle away at the ‘yard to keep your opponent from mining it for value, or it can clean it out in response to a combo or any other dangerous play. And it cantrips on top of all of that. Highly recommended as a sideboard piece to bring against combo, control, and midrange decks, and in some metagames it's even mainboard-playable. Mainboard or Sideboard
Sorcerous Spyglass – This card is narrow, but it eliminates some of the guesswork involved in naming a specific card by giving you a chance to peek at your opponent's hand first. The inherent value of information is hard to quantify, but what is clear is that it's helpful to have, and this card's main effect can shut down annoying effects, especially from opposing combo pieces. Sideboard
Creatures:
Benthic Biomancer – While a cheap creature with what is usually a one-time loot effect may not seem impressive in a vacuum, Merfolk is a deck that makes very good use of those effects in the mid-to-late game, as extra copies of Aether Vial or lands beyond what you need to cast your spells are essentially dead cards. Getting that effect in addition to a 1-drop that can also help you curve out and be aggressive is quite handy, especially considering that it permanently pumps itself in the process. Mainboard
Coralhelm Commander – While this card won't be winning any races, it provides several effects we crave in flying and the ability to pump the team. It makes for a quality mana sink, which is something many versions of Merfolk lack. It takes a particular kind of Merfolk 75 to make this good, but it's very good if you do have the right conditions for it. Mainboard
Cursecatcher – While it seems a bit unassuming at first, this card can be a helpful tempo piece against combo decks looking to go over the top on you early and removal-heavy decks that are trying to kill your more dangerous Merfolk. Furthermore, it can serve as early pressure until its effect is called upon. This kind of flexibility and disruptive capability is always welcome in a tempo deck like Merfolk. Mainboard
Harbinger of the Tides – One of the most potent disruptive Merfolk we have access to. Its bounce effect combined with a relevant body can be a huge tempo swing in our favor, and its flash option makes it even more flexible. Additionally, it has great synergy with Merrow Reejerey (tap an opponent’s creature on casting, bounce the creature with Harbinger's enters-the-battlefield ability) and Merfolk Trickster (tap a creature on your opponent's turn, bounce it on your turn). Mainboard
Kira, Great Glass-Spinner – One of the nicer tricks in the Merfolk toolbox, Kira helps keep your creatures safe against targeted removal in addition to providing an emergency flying attacker/blocker. Not being a Merfolk and costing 3 mana (including 2 U symbols) are real downsides, but it’s something that you can work around. Good in either the main or the side. Mainboard or Sideboard
Kopala, Warden of Waves – A handy little 3-drop that helps protect our team while benefiting from all of our tribal synergies. While a tax effect is generally not considered to be as powerful as Kira's counterspell effect, it has very good synergy with cards like Cursecatcher and Spell Pierce, and is unique among the protection effects we have available in that it can ward off uncounterable kill spells like Rending Volley and Abrupt Decay (at least for a time). That combined with the fact that he can get pretty big in this deck thanks to the Lord effects have made him a welcome addition to the Merfolk toolbox. Mainboard
Master of Waves – This is the deck’s haymaker. Protection from R and CMC4 means it shrugs off a lot of common removal spells, and its enters-the-battlefield token-generating effect often creates insurmountable board states (or protects you from whatever your opponent has going on). Not the greatest against fast combo decks, but excellent otherwise, and highly recommended. Mainboard
Merfolk Trickster – Tapping a creature and removing its abilities is quality interaction, and getting a flash Merfolk body is just icing on the cake. This is a very powerful catch-all creature, and likely to become a part of Modern Merfolk's core in the near future. Mainboard
Merrow Reejerey – Another Lord effect, should you need it. While its effect isn’t as offensively potent as the 2-mana Lords, it’s a very versatile one. You can use it as pseudo-ramp by untapping your own lands or Aether Vials, as evasion by tapping your opponent’s creatures, or defensively by untapping your Fish after an attack. A very flexible and useful card. Mainboard
Mistcaller – While this little guy's effect is conditional, it's often quite a blowout when it does come to pass. It's relevant against reanimator decks like Dredge and Grishoalbrand, creature-combo decks with cards like Chord of Calling, Collected Company, Eldritch Evolution, and Neoform and it can be used to delay Aether Vial activations (just bear in mind that the Vial's controller can choose to not use the artifact after you activate it), and it's a cheap Merfolk body to project your buffs on against the rest of the field. It can definitely shine in the right metagame. Mainboard or Sideboard
Phantasmal Image – This card can be very flexible in that you can either copy your own creatures to get more of an effect you wanted (be it pump, card draw, tokens, or disruption), or something cool that your opponent is doing (especially if you'd have a hard time responding to it otherwise). However, it is very fragile (it can die to something as innocuous as a pump spell or a tap effect). Moreover, most of our traditional ways to protect creatures (counterspells, Kira, Great Glass-Spinner, Spellskite) can’t save it. It's also worth noting that it's not a Merfolk while in your hand or being cast, so it interacts poorly with Cavern of Souls, Merrow Reejerey, Silvergill Adept, or Wanderwine Hub. It can be very powerful, but it has to be used judiciously. Mainboard
Phyrexian Revoker – Mostly analogous to a Pithing Needle effect, this one offers some additional upside on our end by virtue of being a creature. That means that you can use Aether Vial to flash it in while a palatable target for its effect is on the stack, and that it can attack your opponent. Furthermore, our deep suite of dangerous creature threats makes the opponent’s choice on what creature to use spot removal on more difficult. Lastly, while this card cannot affect the likes of utility lands, it can affect mana abilities on nonland permanents. This can be quite important, and makes the Revoker quite versatile in what kind of permanents it can answer. Sideboard
Spellskite – This card is interesting in that it can be used both offensively as disruption to decks that rely on targeted effects (such as Aura Hexproof/Bogles, Burn, Infect, and UR Prowess), or defensively to soak up damage-based removal. It’s not much to look at in terms of pressure (I'd suggest looking at it as a noncreature spell when determining how many threats are in your deck), but it can help protect your pressure as it takes down your opponent. At its best as a sideboard bullet, where it can dodge artifact hate and only come in to ruin your opponent's day. Sideboard
Thassa, God of the Sea – Scrying every turn before you draw can be a potent advantage, and getting to devotion 5 (note that it counts itself for this purpose, as well as cards like Spreading Seas) gives you access to a powerful indestructible beatstick. Unblockability for 1U can also be handy in situations where your islandwalk isn't live. While 3 mana is a bit on the expensive side, I consider it to be helpful in avoiding Merfolk's main internal issue in flooding, and thus worthy of seeing play. An important thing to keep in mind is that indestructible does not save this creature from dying to Dismember or Path to Exile when it is in creature form. Mainboard
Tidebinder Mage – This card’s effect is narrow enough that it belongs in the sideboard in most metagames, but it makes for one heck of a sideboard card. Tapping your opponent’s creature down indefinitely is oftentimes as good as removing it (and sometimes it's even better), and you get a body of a relevant type as a bonus. Sideboard
Vendilion Clique – While this card is not a Merfolk and is also a bit tricky in terms of mana cost, it fills a need by being a flier with an aggressive body and having a disruptive enter-the-battlefield effect. Very potent if you're expecting big mana, all-in combo decks, and sweepers. Mainboard or Sideboard
Venser, Shaper Savant – This guy is on the expensive side (and isn't a Merfolk), but it offers a truly unique tempo effect capable of doing things no other card can (e.g. bouncing Supreme Verdict to buy your rush one more turn). The fact that it brings a 2/2 body along can't be ignored, either. His best application is as a sideboard haymaker to decks vulnerable to this sort of tempo-intensive play, and he's good at that role. Sideboard
Enchantments:
Sea's Claim – This card can combine with Spreading Seas to basically shut your opponent out of their lands if they’re not running U. Not terribly useful against U-based decks (though we’re typically favored against those anyway), but it can be devastating to any deck relying on a 3-color manabase or otherwise depend heavily on their lands (BGX, Burn, Death's Shadow, Eldrazi, Tron, and Zoo, for example). My recommendation for this card is to run it in the sideboard and bring it in where it can be most effective, but it has also been employed in the mainboard to good effect. Mainboard or Sideboard
Instants:
Ceremonious Rejection – A very cheap and efficient tool with which to stymie the likes of Affinity, Eldrazi, and Tron decks. It's a bit narrow and can be shut off by the likes of Cavern of Souls, but it's crazy good if you manage to connect with it. I think that this card can be a viable substitute for Merfolk's more traditional land hate sideboard package, and thus should play a prominent role in the sideboards that choose to feature it. Sideboard
Deprive – While it is not always trivial to come up with the UU to cast this card, countering any spell with no conditions other than returning a land (which Aether Vial and a low curve can make less of an issue) is very powerful. A great catchall piece of interaction that can put in good work in either the mainboard or the sideboard. Mainboard or Sideboard
Dismember – Probably the best removal spell we have access to by default. It can be sometimes be painful to cast, but hard removal against most relevant creatures in Modern is worth the pain. Merfolk players have used this in both the mainboard and the sideboard, depending on what the metagame context dictates. Mainboard or Sideboard
Echoing Truth – A nice catchall bounce effect, its ability to bounce copies can come up big against tokens and other decks that like multiples of a same effect on the board (including the mirror match). A strong card that I recommend for the great majority of Merfolk 75s, and some metagames even dictate that this be a maindeck inclusion. Mainboard or Sideboard
Gut Shot – It doesn’t look like much at first glance, but this can provide you with a potent early tempo advantage by zapping small creatures (especially mana dorks like Arbor Elf, Birds of Paradise, or Noble Hierarch) at the cost of a bit of life. Definitely playable in your sideboard, even if it's not the flashiest. Sideboard
Hibernation – A great hoser out of the sideboard, this card comes up huge against the likes of Aura Hexproof/Bogles, Elves, and Zoo, flipping tempo in your favor. However, it’s a bit up there in terms of mana cost, so it can be a bit awkward to cast at times. Sideboard
Hurkyl's Recall – A mass bounce effect for one of the permanent types that we need it most. It can be a life-saver against the likes of Affinity, 8-Rack, Lantern Control, and Whir Prison out of the sideboard. Sideboard
Negate – A very effective and versatile counterspell, especially against big-mana decks like Tron and Valakut that can just pay the extra cost imposed by a card like Spell Pierce. A strong sideboard card. Sideboard
Remand – While it doesn’t get rid of whatever it targets permanently, the tempo boost you get from sending it back up to their hand makes it worth your while, especially given that you get to draw a card afterwards. I think that it fits in well with our primary gameplan, and can play an important role in either the main or the side. Mainboard or Sideboard
Spell Pierce – A great catchall counterspell for most things Merfolk doesn’t want to see resolved, it also has the benefit of being cheap and easy to sneak into a curve. Not the most individually potent card, but its flexibility and speed are major assets. Mainboard or Sideboard
Unified Will – As a creature-based tempo deck, Merfolk will often have more boots on the ground than its opponent, and that makes this a powerful hard counter to bring in out of your sideboard at a reasonable mana cost. At its best against combo or control decks, where there are important spells to counter and few bodies to interfere with its ability. Sideboard
Vapor Snag – Bouncing a creature is a nice tempo play, and tacking on a life loss effect on top of it makes it even nicer. You can even use it to save your own creatures in case of an emergency. I think it's an integral piece of our disruption package, and is thus mainboard-worthy. Mainboard
Lands:
Cavern of Souls – Makes your Merfolk uncounterable, which is a nice perk to have against control and opposing tempo decks. However, it has a notable downside in that it can only produce U for your Merfolk, which can sometimes complicate the business of casting creatures while leaving mana up for interaction purposes, or casting some of our useful toolbox creatures. Because of this, most players that play this card opt for less than the full playset. Even with this drawback, the effect is strong enough to be worth considering. Mainboard
Faerie Conclave – Not exactly the first thing that springs to mind when you think "Merfolk", but it's a land that produces U (check), can make good use of your excess mana (double check), and can turn into a flying attacker or blocker (triple check). It requires a bit of maneuvering in order to use effectively, but it has proven to be a handy part of the Merfolk arsenal. Mainboard
Fiery Islet/Waterlogged Grove – These lands produce U, and can be cashed in for a card if you have excess lands. This sort of effect is very useful in Merfolk, which doesn’t have that many mana sinks, and also has Aether Vial to help with its mana production requirements. Very handy cards. Mainboard
Minamo, School at Water's Edge – It protects you from Boil, Choke, and giving up islandwalk in the mirror match. It can also be a sneaky on-board trick if you happen to have a legendary creature on the battlefield (and we run those on occasion). Most Merfolk manabases can and should make room for it. Mainboard
Oboro, Palace in the Clouds – This is Boil/Choke/mirror protection, and it has a sneaky-good interaction with any of your C-producing lands when you're short on land drops, but really need U mana (tap Oboro for U, tap any other land for the 1 to bounce Oboro, replay Oboro and tap for U). Last but not least, you can beam it back up to your hand if you need to discard a card for something like a Benthic Biomancer's adapt ability or a Liliana of the Veil activation. Highly recommended as a mainboard 1-of. Mainboard
Tectonic Edge – This is one of Merfolk players' preferred pieces of land hate. It's uncounterable by virtue of being a land, works at card parity, hits a wide variety of targets (shocklands, manlands, Tron lands, Eldrazi Temple, Valakut, the Molten Pinnacle, etc.), and it's relatively inexpensive to use. Bringing this card in from your sideboard can really ruin some opponents' days. Sideboard
Wanderwine Hub – This card gives you U while keeping you safe from the likes of Boil, Choke, and enabling islandwalk in the mirror, and it even gives you W if you're into that sort of thing. The tapland drawback is basically negligible in a tribal deck like ours, which makes it a fine choice. Mainboard
Experimental Card Choices:
This is an addendum to the Preferred Card Choices section, and contains cards that haven't put up much in the way of concrete and notable results, but could be interesting additions to the deck. Try these out at your own risk, and be sure to report back on how they do!
Artifacts
Sentinel Totem – A similar card to Relic of Progenitus, except it downgrades the ability to replace itself to a scry 1 in exchange for not needing to hold up mana in order to wipe the graveyard. Should you feel that the mana needed to babysit Relic is holding you back in certain matchups, this could be a palatable alternative.
Smuggler's Copter – While this card has power and toughness values, it's best to think of it as a utility boost to any one of your creatures - it can enable you to get damage in on board states where you otherwise wouldn't (for example, in a ground stall where you don't have islandwalk), and the flying can be valuable on the defensive end. Furthermore, the looting effect is quite handy at smoothing out some of our clunkier draws. A handy little card to have. Mainboard
Creatures
Cosi's Trickster – Likely the most aggressive 1-drop we have access to as Merfolk, this one can take advantage of your opponent using effects like fetchlands, or shuffles forced by your own effects (Ghost Quarter, for example) to grow pretty big. Mainboard
Mothdust Changeling – This guy is interesting because it provides an ability Merfolk finds hard to come by (flying). Unfortunately, you have to tap a creature to get it, which is not ideal. Still, it has some potential as a 1-drop if you find that you really need early-game flyers. Mainboard
Skaab Ruinator – An interesting option in removal-heavy matchups, its large size and ability to self-recur are undeniable assets in a drawn-out game. It also can be Vialed in to remove its initial casting requirement. It's not a Merfolk and it doesn't help your team beyond being big (which are real strikes against it), but it still has some potential. Sideboard
Tideshaper Mystic – While it doesn't quite disable lands the way Spreading Seas can, having a creature that can switch on islandwalk and help you force damage through when needed is still a pretty handy thing to have. An interesting experimental option. Mainboard
Watertrap Weaver – Don't be fooled by the somewhat unassuming base stats; this card is a beating against virtually any opposing creature deck by virtue of its ability, and the fact that it's a Merfolk means it can get pumped to the point where it is a threat. A bit overshadowed by Merfolk Trickster, but available shoud you want additional copies of the tapdown effect. Mainboard
Enchantments
Deeproot Waters – While this card is very slow (as it does not affect the board when it enters the battlefield) and somewhat at odds with Aether Vial (as it requires that you actually cast your Merfolk), it has some potential as a substitute for the Vial in attrition matchups. Flooding the board with hexproof Merfolk can really be a thorn in the side of midrange and control decks, particularly when they have some Lord effects to back them up. A card to consider. Sideboard
Monastery Siege – This card is pretty versatile, but it’s a bit on the slow side. Both of the modes can help you against attrition-based decks (and the Dragons mode is pretty good against the likes of BGX, Grixis, and Burn), but it's a very awkward play in a hand where you don’t draw Aether Vial. It could be helpful, but the extent of how much is somewhat questionable. I think it's strictly a sideboard card. Sideboard
Threads of Disloyalty – A bit off the beaten path, this nonetheless offers a powerful effect. Taking control of the likes of Death's Shadow, or Tarmogoyf, or other undercosted beater can really turn a game around, and if an opponent has no enchantment hate, they might be forced to remove their own creature, adding insult to injury (not to mention provide you with card advantage). Its range is narrow enough that I can't justify it in the mainboard, but it's a potent sideboard effect. Sideboard
Instants
Cryptic Command – While expensive and hard to cast, this card's raw power and flexibility is undeniable. It can interact with the opponent on the stack or on the board, and usually replace itself to boot. If you're looking for an off-the-beaten-path inclusion for Merfolk's top end, perhaps this is worth a try. Mainboard
Disdainful Stroke – If you're looking to defend against cards like Primeval Titan, Collected Company, and pretty much anything that matters out of Eldrazi or Tron, this card is a strong option. It's also very strong against control decks, since many of their midgame haymakers are within range. Worth some consideration. Sideboard
Disrupting Shoal – While certainly unorthodox, this counterspell has some potential in Merfolk, given that this is a mono-colored deck with cards at a variety of different mana costs to pitch to it (especially for x=2, which is a popular mana cost for opponent's spells) and it also helps free up your mana to develop your board and still keep shields up. It's unproven, but it could be very powerful. Mainboard
Flashfreeze – While narrow, this counterspell catches a lot of very potent spells, ranging from sweepers like Pyroclasm and Anger of the Gods to game-winning effects such as Primeval Titan and Scapeshift. If you don't want to let a problematic spell resolve, this seems like a strong option. Sideboard
Mana Leak – A decent counterspell. Its "tax" effect combined with its 2 CMC means it won't always be live, but it's plenty powerful when it is. Its catchall nature makes it a good mainboard inclusion for those inclined to test it, but I wouldn't recommend it as a sideboard card. Mainboard
Peek – While information is inherently valuable, the exact impact of it is hard to quantify. This currently offers you a good amount of that, while being cheap and replacing itself. If you're in the market for seeing what your opponent is up to, this is likely the best rate currently available in mono-blue. Mainboard
Pongify/Rapid Hybridization – Unconditional removal is a pretty good thing to have, and while this card leaves behind a 3/3 token, that's often something Merfolk can beat (especially with something like Harbinger or Tidebinder). It requires a bit of effort to use effectively, but it might be useful. Mainboard
Repeal – This card is somewhat mana-intensive, but a tempo play that can hit any nonland permanent with card draw attached is the sort of powerful catchall effect Merfolk is always in the market for. It will require a specific kind of Merfolk 75 and opposing metagame to be successful, but if you find yourself in those circumstances, it can be a very strong choice. Mainboard
Spell Snare – While this card is narrow, many decks in Modern rely on 2-drops, and some do so quite heavily. Having a piece of interaction that's live on the draw and easy to keep mana open for has some potential, and it can always be sided out if it's poor against a given opponent. This card has not been used by many Merfolk players, but perhaps it should be kept in mind as an option. Mainboard
Swan Song – The drawback might scare some people away, but it’s a decent cheap counterspell to bring in from the sideboard against the likes of combo decks. A 2/2 flier can’t outrace a Merfolk deck on its own, and shutting down their combo will give you the opportunity to race. Sideboard
Thassa's Rebuff – While a bit on the win-more end (this only becomes a potent counterspell once you've established a board state), this can potentially serve an important purpose in Merfolk, which is as a catch-all to ensure your opponent does not mount a comeback once you are ahead. I can see the upsides and downsides to it, but it's hard to tell which outweighs the other without more testing. Sideboard
Unsubstantiate – A very flexible spell, this card is basically half a Remand stapled to an Unsummon, with the bonus of that it can hit uncounterable spells such as Abrupt Decay, Volcanic Fallout, and Supreme Verdict. However, the fact that it is purely a tempo play makes its applicability questionable. It has some potential. Mainboard
Wizard's Retort – While this card's discount effect (which is the major thing that makes it a playable consideration) keys off Wizards as opposed to Merfolk, many of the Merfolk that see play in Modern happen to be Wizards. If you don't feel like you have enough catchall counterspells for your liking, this may be something to consider. Sideboard
Lands
Gemstone Caverns – This land is an interesting option for "stealing" the play and making sure you can keep up on board development. While losing a card is a harsh cost, it can be very useful in openers where you don't have an Aether Vial, or are looking to slam something like a Chalice of the Void as soon as possible. Might be worth a test. Mainboard
Lonely Sandbar – While being a tapland is an undeniable drawback, the fact that you can cash these in for a card if you have excess lands make them pretty handy. It's unclear whether a redraw is better for us than the creature-land effect of something like Faerie Conclave, but it's probably worth experimenting with. Mainboard
Planeswalkers
Ashiok, Dream Render – This card doubles as search hate and graveyard hate, which makes it useful in a variety of matchups. While 3 mana for a noncreature spell is a bit on the high end of what we'd like to pay, effects this definitive may be worth it if you expect to face the decks that seem most susceptible to its static effect (Primeval Titan decks, Whir of Invention decks, and possibly graveyard decks, if used as a supplement to more conventional graveyard hate).
Budget Options
This section is dedicated to finding somewhat cheaper alternatives to some popular cards, as the likes of Aether Vial, Cavern of Souls, and Mutavault can be pretty expensive from the real-world point of view.
Ghost Quarter – If you can't afford Mutavaults, this is a handy little disruptive land that can punish big-mana decks and eat up manlands, and it can also target one of your lands if you happen to be starved for U. You can do worse. Mainboard
Merfolk Sovereign – In the event that you're finding some of the Lords a bit hard to come by, this can offer you a bit of extra pump and an unblockability effect in case you're having trouble evading blockers. Mainboard
1. Use Aether Vial for early pressure. A T1 Vial can help you put a lot of boots on the ground quickly, and that can overwhelm an opponent that's not equipped to deal with multiple creatures hitting the table in rapid succession. This will get you a lot of free wins.
2. Aether Vial helps your creatures dodge counterspells and removal. Remember that the Vial's effect can be used any time you could play an instant – this means you can flash creatures in as a combat trick (for example, using a Harbinger of the Tides to erase an attack or a Lord to mess up your opponent's combat math). You can also bring your creatures in on your opponent's end step in order to dodge sorcery-speed removal (this is especially important against sweepers like Supreme Verdict).
Another note is that because the creatures are being put into play via the Vial's activated ability, they are not being cast. That means that opposing counterspells do not work. On the bad side, it also means they won't trigger the likes of Merrow Reejerey.
3. Aether Vial's charge counter effect is optional. That means you don't have to tick it up if you don't want to. This is especially relevant in Merfolk, because the deck is crawling with useful 2-drops that you'll want to get on the battlefield as quickly as possible. As such, I would recommend you think long and hard before you tick up your Vial from 2 charge counters.
4. Aether Vial can help you be aggressive and interactive at the same time. While I did mention that being aggressive with Vial can get you free wins, there are decks that strategy doesn't work against, namely fast combo decks. In that case, you can use your Vial to keep steady pressure on your opponent while you hold up some form of disruption (usually bounce or counterspell effects) to stuff whatever they're up to.
To Splash, or Not to Splash?
One of the major decisions a Merfolk player has to make when creating his or her deck is to decide whether to splash for a second color. Most Modern decks are multiple colors, in large part because the versatility provided by the larger toolbox is necessary in order for the deck to function competitively.
This has NOT the case for Merfolk historically – the mono-U build has been the most competitive variant for a long time, and the reason why was the excellent consistency in the mana base thanks to only needing U mana for spells, and (to a lesser extent) the lack of self-inflicted damage by opting to stay away from fetchlands and shocklands. Because of this, the answer to the question posited at the start of the section in the past was NOT TO SPLASH. For more on that, check out Nikachu_'s informative video on why the W splash wasn't worth it in the past.
However, recent additions to the card pool have changed this paradigm. One potential splash that seems to be a strong option is UG Merfolk (aka Tropical Fish, hat tip to Reddit). The reason why this variant stands above the rest is because it features a significant amount of quality creatures with the Merfolk type, thanks to Ixalan and Rivals of Ixalan. If you are dead-set on splashing a color in your Merfolk deck, I strongly recommend that it be G in order to take advantage of this creature selection. Here are some of the options available to a pilot that does so:
UG Merfolk/Tropical Fish:
Botanical Sanctum – You need access to G without compromising your U source count, and this is the best option available that doesn't cost you life. Essential to making this splash work. Mainboard
Breeding Pool – About as good a source of U and G as you’re going to find in Modern. Mainboard
Collected Company – While this card is undeniably powerful, I'm of the opinion it's a bit of an awkward fit in Merfolk, due to its high cost and Merfolk's lack of conventional mana acceleration. However, if you're looking for card advantage in UG colors, it's hard to do better. Mainboard
Heroic Intervention – While this is a somewhat clunky card, it is a way to protect your entire team from sweepers such as Supreme Verdict, which is something few cards in the Merfolk toolbox are capable of doing. Worth considering. Sideboard
Kumena, Tyrant of Orazca – While this card runs somewhat at odds with Merfolk's aggressive gameplan, its effects combined with its resilient body make it an interesting option if you expect games to go long. Mainboard or Sideboard
Kumena's Speaker – If you want to streamline your deck and make it more aggressive, this is a quality 1-drop with the right creature type. Mainboard
Jungleborn Pioneer – 2 bodies for 3 mana is a pretty solid rate, and the fact that one of them has hexproof is also pretty interesting. Worth considering. Mainboard
Merfolk Branchwalker – While this card is definitely no Silvergill Adept, a 2-drop that can get you a bit of value upon entering the battlefield is far from a bad thing. A card to consider in certain shells. Mainboard
Merfolk Mistbinder – Another 2-mana Lord effect is a major incentive for splashing G, and it allows you to lower the deck's curve in a significant manner. I consider this an essential component of the Tropical Fish variant. Mainboard
Flooded Strand/Misty Rainforest/Polluted Delta/Scalding Tarn – Because Merfolk is a U-based deck, and I do not recommend that you play any basic land other than Islands, it does not matter which fetchland you use - all of them can find your shocks, and thus all of them are helpful at making sure your mana is as clean as it can be. Mainboard
Natural State – A cheap and convenient way to remove most troublesome artifacts and enchantments that Merfolk would care about. Zaps everything from Cranial Plating to Ensnaring Bridge to Ghostly Prison, and as such has value. Sideboard
Reclamation Sage – Kills any artifact or enchantment, and is a creature (which makes it Vial-friendly). What's not to like? Sideboard
Shapers' Sanctuary – This card is a nice way to ensure your gameplan won't get run out of gas by copious amounts of spot removal. One of the nicer tools made available by the G splash. Sideboard
For completeness' sake, I am also including some card options in other colors below:
WU Merfolk:
Blessed Alliance – This can be a powerful tool against decks that like to come in with pump spells and large attackers (Bogles, Death's Shadow, Eldrazi, Infect, UR Prowess), and of course is handy against Burn. A pretty good card to have. Sideboard
Disenchant – Not a fancy effect, but a useful one. U doesn’t really have many ways to blow up permanents once they hit play, and this card fixes that problem. Strictly a sideboard card, though. Sideboard
Hallowed Fountain – It’s not as smooth as some of the other W sources we have access to, but it’s fetchable and thus does the job. Mainboard
Harm's Way – This is a sneaky little trick to unleash on your opponent. Shifting damage around is a great way to turn a combat situation on its head, and it oftentimes turns a Lightning Bolt played as a removal spell into a removal spell for you. A bit tricky because you have to hold up W until the right moment, but the payout is well worth it. Could be run in either the main or side. Mainboard or Sideboard
Kataki, War's Wage – A potent way to severely damage Affinity decks while not really damaging your own hopes. His only weakness is his 2/1 body, which is quite easy to remove. Quality sideboard material. Sideboard
Militia Bugler – While not a Merfolk in its own right, its value effect synergizes very well with a deck that has lots of small creatures it makes dangerous with pump effects. A bit experimental, but if you're looking to grind, you'll be hard-pressed to find a better effect on a creature in this format. Mainboard
Rest in Peace – Arguably the most potent piece of graveyard hate available to you, it being on the field can basically win you the game against a deck that’s dependent on the ‘yard. It's narrow enough that it should come in off the sideboard, though. Sideboard
Seachrome Coast – Painless source of W that doesn’t compromise your U source count? Sign me up! Mainboard
Stony Silence – This usually stops Affinity cold when it hits the board, but it should be noted that it doesn’t play nice with our Aether Vial. Still, anything that houses our worst matchup is worth including in your sideboard, and it does double duty against Tron. Sideboard
Sygg, River Guide – A bit on the slow side, but on-demand protection for your creatures is a juicy carrot. However, the mana-intensiveness of the effect means that you probably won’t get to use it until the later game. Still, it's a reasonable on-tribe body with a powerful effect, and that is worth considering. Mainboard
Worship – This card is a haymaker against creature-based aggro decks with limited ability to interact with non-creature permanents, and can sometimes just win you games outright. It’s on the expensive side, though, so casting it can sometimes be a bit of a challenge. I would consider this a sideboard card, but a good one. Sideboard
UB Merfolk:
Collective Brutality – While Merfolk isn't exactly the kind of deck that likes pitching cards from its own hand (unless they're extra Aether Vials), this effect can be quite handy at shutting down fast decks that rely on a combination of creatures and spells to kill you quickly (Burn, Devoted Company, Elves, and Infect being the major examples). Worth considering. Sideboard
Darkslick Shores – If you’re going to splash B, a painless source of it is invaluable. Mainboard
Fatal Push – Quality removal for most creatures you care about. One of the main reasons to consider the splash. Mainboard
Inquisition of Kozilek – Early game disruption can make for a potent T1 play, and it has tons of relevant targets in Modern. Its only flaw is that it requires us to splash. It probably takes the place of some of the counterspells that other Merfolk 75s would play. Mainboard or Sideboard
Thoughtseize – One of the greatest T1 plays you could have, its only flaw is that it requires B. The life loss can also sting when you’re already damaging yourself to be able to cast it in the first place. It mostly serves as a counterspell-substitute. Mainboard or Sideboard
Watery Grave – Probably your most reliable source of B while not neglecting U. Plays nice with fetches, so you’ll need it. Mainboard
UR Merfolk:
Blood Moon – This card synergizes with Merfolk's innate land hate plan in order to lock most opponents out of the game. Can be a potent maindeck hate piece in certain metagames, but overall it's likely at its best coming in off the board as a shutdown piece for decks soft to it. Mainboard or Sideboard
Electrickery – A potent sideboard bullet against weenie-based decks, this can blow up board states that have gone too wide for you to deal with otherwise, and it'll do so for cheap. Useful card to have in your toolbox. Sideboard
Izzet Charm – This is basically the Deluxe Edition of Spell Pierce. It costs more mana, but it adds 2 potential modes, so it's never a dead card in hand. Worth considering. Mainboard or Sideboard
Izzet Staticaster – This card offers repeatable elimination of swarms of creatures, provided they have the same name. As that heavily implies, it's at its best when handling tokens, which is something that Merfolk can have trouble with on the occasions we can't just islandwalk past them. It's a nice backup plan if you expect to see lots of tokens. Sideboard
Lightning Bolt – The workhorse burn spell of Modern. We've felt its wrath many a time, so we know how good it can be to clear blockers, remove attackers, disrupt combos, or just finish off wounded opponents. You won't need much more bounce or removal if you're packing this. Mainboard
Steam Vents – This is about as good a source of R as you'll find. Pack it and figure the rest out later. Mainboard
Spirebluff Canal – While fastlands can be inconvenient if they're your 4th land drop, a painless source of U and R is critical in order to pull this splash off. Mainboard
Wizard's Lightning – This card's effect keys off a different tribe than Merfolk, but it's a tribe Merfolk has a lot of overlap with. If you find yourself wanting more than 4 Bolt effects when running this splash, this may be a worthy consideration. Mainboard
Merfolk (also known as Fish) is a U-based tempo deck with a strong aggro secondary element that is built around tribal synergies. Merfolk is a mostly fair deck, with most iterations striking a balance between being linear and proactive, and being interactive and reactive. It employs lots of cheap, efficient creatures along with Aether Vial and some catchall disruption in order to overwhelm its opponents. For a more thorough (though somewhat outdated) overview of the Merfolk deck, check out Merfolk Joe's Guide to Modern Merfolk video series.
Why Merfolk?
Here are some reasons why you might consider Merfolk as the deck for you:
Versatility – oftentimes in Modern, a deck has to choose between being fast and aggressive or being able to disrupt its opponents. Not so for Merfolk – you can often do both at the same time, especially with an Aether Vial on the table. We can play the aggro game, we can focus on disrupting our opponent and being more of a tempo deck, or even build up into a big bomb that blows open a stagnant board state, midrange-style.
Competitiveness – in a format as wide-open as Modern, a deck that performs well against the field is potent. Merfolk has very few outright bad matchups (mostly artifact-based decks), and plenty of matchups that are 50/50 or better. This makes it a strong choice for all-comers tournaments.
Nuance – you wouldn’t think that an aggressive deck that relies on creatures is all that difficult to pilot, but Merfolk has several different lines of play available to it. This is most often the case when you have to choose between allocating your resources toward disrupting your opponent's gameplan or committing to advancing your own. Recent sets have also provided us with an interesting lineup of creatures that both disrupt the opponent and provide on-tribe bodies to project our Lord effects on.
Resilience – there are a lot of decks out there that require a certain type of hand in order to be successful, and have to mulligan if they don't have it. Merfolk obviously can’t overcome a total lack of lands and/or creatures, but the deck is pretty resistant to mulligans overall. Furthermore, the deck has proven to be capable of overcoming disruption, even disruption specifically tailored against it.
Links:
Here are a few links you can check out if you want more Merfolk content.
Nikachu's YouTube Channel – Nikachu is a very seasoned Merfolk player that has a deep repository of videos you can peruse to get up to speed on how to play Merfolk. Merfolk Joe's YouTube Channel – Merfolk_Joe is another seasoned Merfolk player, and he has some very polished and informative videos of Merfolk in Modern. LordMajicus' YouTube Channel – LordMajicus is a veteran Merfolk pilot that runs both stock and innovative lists on Magic Online. The seer's YouTube Channel – Here is another channel with one of our fellow Merfolk players testing the deck against the field. MagicMaxe's YouTube Channel – This channel has videos of paper matches for Merfolk for both Modern and Legacy. FishMTG Subreddit – An entire subreddit community focusing on Merfolk decks. Some alternative discussion to be found here. Petr Sochurek's Merfolk primer – Petr is widely regarded as one of most influential voices in constructing Modern Merfolk as we know it, and he has recently released a 3-part primer series discussing the deck in great detail. Nicholas Bradley's Summary of Merfolk in the Meta – This is a seasoned Merfolk player's take on the deck and its matchups. FishMTG Discord – If you want to discuss Merfolk in real time, this is a Discord server dedicated to our deck across formats.
Note: Please post your decklist (including sideboard) when asking for advice on this thread. Help us help you.
02/11/2016 - Added Sea's Claim to the "land hate" category in the Matchups and Sideboarding section where appropriate. 02/15/2016 - Updated the Matchups and Sideboarding section where appropriate. 02/17/2016 - Updated the description for Chalice of the Void in the Preferred Card Choices section. Updated Sample Decklists section. 02/22/2016 - Added Grafdigger's Cage to the Preferred Card Choices section and the Matchups and Sideboarding section where appropriate. Added MagicMaxe's YouTube channel to the Links section. 02/25/2016 - Updated the Matchups and Sideboarding section where appropriate. 02/29/2016 - Added Pithing Needle to the Matchups and Sideboarding section where appropriate. 03/03/2016 - Updated the Matchups and Sideboarding section where appropriate. 03/16/2016 - Updated the Modern Merfolk Core Decklist and the Matchups and Sideboarding sections where appropriate. Added Dario Casati's list to the Sample Decklists section. 03/27/2016 - Added Essence Flux, Invasive Surgery, and Threads of Disloyalty to the Preferred Card Choices section and the Matchups and Sideboarding section where appropriate. 04/05/2016 - Added Stonybrook Banneret to the Budget Options section. 04/11/2016 - Added Budget deck to the Sample Decklists section. 04/23/2016 - Updated the Sample Decklists section where appropriate. Added Sea Gate Wreckage to the Preferred Card Choices section and the Matchups and Sideboarding section where appropriate. 04/26/2016 - Added MerfolkJoe's YouTube channel to the Links section. 04/29/2016 - Updated the Matchups and Sideboarding section where appropriate. 05/04/2016 - Updated the Matchups and Sideboarding section where appropriate. 05/10/2016 - Updated the Sample Decklists section where appropriate. 05/18/2016 - Updated the Sample Decklists section where appropriate. 05/22/2016 - Added Simon ****sky's and Przemek Knocinski's Merfolk lists to the Sample Decklists section. 05/23/2016 - Edited the Links and Sample Decklists sections as appropriate. 06/08/2016 - Updated the Matchups and Sideboarding section where appropriate. 06/27/2016 - Updated the Sample Decklists section where appropriate. 06/29/2016 - Edited description for Remand in the Preferred Card Choices section. 07/08/2016 - Updated the Sample Decklists section where appropriate. 07/20/2016 - Updated the Preferred Card Choice section where appropriate. 07/26/2016 - Added Merfolk Joe's Guide to Modern Merfolk and Petr Sochurek's Merfolk primer to the Introduction and Links sections, respectively. 07/27/2016 - Updated the Matchups and Sideboarding section where appropriate. 07/28/2016 - Added the Experimental Card Choices section and updated the Modern Merfolk Core Decklist and Sample Decklists sections. 08/01/2016 - Updated the Sample Decklists section where appropriate. 08/14/2016 - Updated the Sample Decklists section where appropriate. 08/17/2016 - Edited Introduction and Why Merfolk? sections where appropriate. 09/08/2016 - Updated the Matchups and Sideboarding section where appropriate. 09/21/2016 - Edited the spelling of Aether Vial to accomodate the new printing. 09/27/2016 - Added Flashfreeze to the Experimental Card Choices section. 10/13/2016 - Updated Introduction section and Merfolk Joe's Merfolk list in the Sample Decklists section. 10/14/2016 - Updated the Matchups and Sideboarding section where appropriate. 10/30/2016 - Updated the To Splash, or Not to Splash? and Sample Decklists sections where appropriate. 11/09/2016 - Updated the Matchups and Sideboarding section where appropriate. 11/17/2016 - Added Skred Red to the Matchups and Sideboarding section. 11/22/2016 - Updated the Matchups and Sideboarding section where appropriate, and edited formatting. 11/23/2016 - Updated the GX Tron and Temur Midrange entries in the Matchups and Sideboarding section. 12/03/2016 - Updated rothgar13's Merfolk list in the Sample Decklists section. 12/05/2016 - Added Blossoming Defense and Fog to the To Splash, or not to Splash? section. 12/23/2016 - Updated the Matchups and Sideboarding and Sample Decklists sections. 12/28/2016 - Updated the primer in general. 01/17/2017 - Updated the Matchups and Sideboarding and Sample Decklists sections. 01/25/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section. 01/30/2017 - Added Smuggler's Copter to the Experimental Card Choices section. 02/06/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section. 02/07/2017 - Updated rothgar13's Budget Merfolk list in the Sample Decklists section. 02/14/2017 - Updated the Matchups and Sideboarding section. 02/21/2017 - Added Vendilion Clique to the Preferred Card Choices section. 03/01/2017 - Added ModernNexus' Merfolk primer to the Links section. 03/15/2017 - Updated the Matchups and Sideboarding section where appropriate. 03/19/2017 - Added Ceremonious Rejection to the Experimental Card Choices section and Vendilion Clique to the Matchups and Sideboarding section. 03/28/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section. 03/31/2017 - Edited the Ad Nauseam entry in the Matchups and Sideboarding section. 04/01/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section. 04/17/2017 - Updated the Matchups and Sideboarding section and rothgar13's Merfolk list in the Sample Decklists section. 05/02/2017 - Updated the Matchups and Sideboarding section. 05/26/2017 - Added the Merfolk List and Sideboarding Guide (by yours truly) to the Links section and updated rothgar13's Merfolk list in the Sample Decklists section. Also updated the Matchups and Sideboarding section. 06/06/2017 - Updated the Sample Decklists section. 06/26/2017 - Updated the Matchups and Sideboarding and Sample Decklists sections. 07/05/2017 - Updated the Matchups and Sideboarding section. 07/29/2017 - Added Nicholas Bradley's Merfolk article to the Links section. 08/04/2017 - Updated the Matchups and Sideboarding section. Added Gemstone Caverns, Pongify/Rapid Hybridization, and Tideshaper Mystic to the Experimental Card Choices section. 08/11/2017 - Updated the Sample Decklists section. 10/12/2017 - Added Kopala, Warden of Waves to the Preferred Card Choices section. Added Sorcerous Spyglass to the Experimental Card Choices section. Updated the Sample Decklists section. 10/18/2017 - Updated the Preferred Card Choices, Experimental Card Choices, and To Splash, or Not to Splash? sections. 11/04/2017 - Added Watertrap Weaver to the Experimental Card Choices section. 12/08/2017 - Updated the Sample Decklists section. 01/10/2018 - Updated the primer in general. 04/25/2018 - Added Damping Sphere and Merfolk Trickster to the Preferred Card Choices section. Updated the Sample Decklists section. 04/30/2018 - Added Deprive to the Recommended Card Choices section. 05/16/2018 - Updated the Sample Decklists section. Added Coralhelm Commander to the Recommended Card Choices section. 07/23/2018 - Updated the Sample Decklists section. Added MHayashi's Merfolk to the Sample Decklists section. Added Repeal to the Experimental Card Choices section. 08/02/2018 - Updated the To Splash, or not to Splash? section. 08/06/2018 - Added the FishMTG Discord link to the Links section. 08/11/2018 - Edited the primer in general. 08/18/2018 - Removed the damaged ModernNexus Merfolk Primer link from the Links section. 09/26/2018 - Addded Venser, Shaper Savant to the Preferred Card Choices section. 10/22/2018 - Updated Nikachu's Merfolk in the Sample Decklists section. Moved Mistcaller from the Experimental Card Choices section to the Preferred Card Choices section. Added Peek to the Experimental Card Choices section. 03/01/2019 - Updated the primer in general. Began overhaul of Matchups and Sideboarding section. 03/25/2019 - Finished the Established Decks sub-section of the Matchups and Sideboarding section. Added Cryptic Command to the Experimental Card Choices section. 03/26/2019 - Updated the Introduction and Why Merfolk? sections. 03/28/2019 - Finished the Fringe Decks sub-section of the Matchups and Sideboarding section. 04/05/2019 - Updated the Preferred Card Choices and Experimental Card Choices sections. 05/07/2019 - Added Thassa, God of the Sea to the Preferred Card Choices section. Updated the Matchups and Sideboarding section. Added LordMajicus' YouTube channel to the Links section. 05/08/2019 - Added Ashiok, Dream Render to the Experimental Card Choices section. 07/15/2019 - Added Force of Negation to the Modern Merfolk Core Decklist section. Added Waterlogged Grove to the Preferred Card Choices section. Added Lonely Sandbar and Phyrexian Revoker to the Experimental Card Choices section. Updated the Matchups and Sideboarding section.
The good news is that none of those cards is above $3 USD a pop (and many are much less than that), so once you get the Vials, Vaults, and Catchers, the financial hard part's over. True-Name Nemesis is a great card, but sadly it's not Modern-legal, so you won't need any more for this edition of the deck.
I wouldn't side out my Lords in the mirror; my opponent has me outgunned if I do. You just have to be judicious as to when you drop them in, because the backswing is going to hurt a ton (hint: try to make it such that there is no backswing). As for the Spreading Seas... they come up huge shutting down Mutavaults, and clearing the way for your troops in the event that Minamo, Oboro, or Cavern are all your opponent has on the table.
-2 Spell Pierce, +2 Echoing Truth. I don't really have much else for it (I've only run into it a handful of times in almost 2 years of playing the deck regularly).
Concerning Phantasmal Image: it's quite a diverse card. Beside all the recently mentioned applications, I liked it in Bogles matchups, in which I copy my opponent's bogle (or other hexproof creature) and then target my bogle-illusion with Echoing Truth to bounce all the opponent's bogles back into his/her hand.
Doesn't actually work. Echoing Truth targets the Image, the Image is sacrificed, and the spell fizzles because it has no legal targets. It's the same reason Path to Exile won't get you a free land when it targets an Image. If that's one of the Image's major selling points, I think it's time you look elsewhere.
Spellskite has its pros and cons. On the one hand, it only needs grey mana, which can be nice. He also vials in on 2, and can be flashed in to eat up removal spells (unlike Kira, Great Glass-Spinner, which needs to be on the table when targets are selected). It's also one of the few ways we can interact with an Abrupt Decay. However, it's vulnerable to artifact hate and doesn't generate pressure on its own. Additionally, this is a deck that is naturally somewhat resistant to the spot removal Spellskite would come in to protect against - we just play a bunch of dudes that perform similar functions, so the pressure's always on. I've opted against it overall, but I can see more creature-light builds (like our 8-Seas variant, for instance) packing it in to ensure the creatures they want on the table stick.
Agreed. It's CMC5, and it requires a deck composition entirely different from what we currently have (plus, the effect isn't even that good given how much investment you need to put in). I wouldn't even consider Noyan Dar, Roil Shaper to be on a Merfolk deck's radar, honestly.
I'd say Bloom is slightly favored, given the T2 oops-I-win factor, but we certainly have plenty of hate we can board in. Everything from counterspells to bounce to Ghost Quarter can help you out here.
Iv been having a bit of trouble with pure U/W controls decks lately. I can not seem to get around a Supreme Verdict . I came up with the idea of putting in Meddling Mage as an answer for that spell.
Thoughts??
Play through Æther Vial, and don't over-extend. Commit enough resources for a quick clock, but don't blow your whole hand on it.
I would main 2, personally, since they slot in nicely for Spell Pierce or Vapor Snag. You could side in 2 for decks that get hit really hard by it, like Bogles (x=1), Delver (x=1), Affinity (x=0,1), Elves (x=1), or even Living End (x=0) and maybe Tron (x=1). That said, be ready to side it out for conventional counterspells against decks that are all over the board CMC-wise, or that have ready access to artifact hate.
Unrelated: does anyone know how to add the show/hide block and the rating bar pieces of code? I'd like to streamline the appearance of the primer.
This section will describe some of the more common named decks in the current Modern metagame, and how Merfolk matches up against them. It will also contain suggestions on good cards to sideboard in or out during the match. All of the recommendations will be made with mono-U Merfolk in mind, as that is the most competitive variant of the deck.
Established:
Affinity (Hardened Scales)
General Impression: Bad matchup
Synopsis: What makes this matchup tough are that they have a wide variety of haymakers that can escalate things out of control. Walking Ballista can both threaten our life total and keep the board clean, whereas Steel Overseer or Arcbound Ravager can get out of hand with even a small amount of support. Pair them with even a single Hardened Scales or Animation Module, and the snowball gets too hard to stop. I have found that the best chance we have in the matchup is to prioritize interacting with them early and often, as opposed to developing our own board, and then transitioning into creature beatdown when they get low on threats. Counterspells come up bigger here than they do for other Affinity variants, as this deck often spends its first turns in setup mode. Catching a Ballista or Ravager coming in can sometimes be the difference between winning and losing.
Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Chalice of the Void), hand disruption (Vendilion Clique, removal (Dismember, Gut Shot).
Side out: Slow haymakers (Master of Waves), small value creatures (Benthic Biomancer).
Affinity (Traditional)
General Impression: Bad matchup
Synopsis: A tough matchup, in part because they feature many flyers that are tough for us to block, as well as ways to pump them. Getting the likes of Harbinger of the Tides and Merfolk Trickster to slow down Arcbound Ravager, Cranial Plating, Steel Overseer, and even Signal Pest is critical to success in this matchup, as is turning the corner quickly once you have stemmed the initial rush. They will try to dump their hand onto the battlefield quickly, so make sure that your interactive spells are cheap and efficient. One thing to watch out for is postboard ping effects and sweepers along the lines of Ghirapur Aether Grid and Whipflare, so try to get your guys out of range (or don't commit that much to the board).
Side in: Bounce (Echoing Truth, Hurkyl's Recall), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Chalice of the Void), hand disruption (Vendilion Clique, removal (Dismember, Gut Shot).
Side out: Counterspells (Deprive, Spell Pierce), slow haymakers (Master of Waves), small value creatures (Benthic Biomancer).
Bogles
General Impression: Close matchup
Synopsis: This matchup is often tough in Game 1, as many Merfolk maindecks aren't well suited to interacting with enchantments and hexproof creatures. The good news is that (depending on the contents of your sideboard) the post-board games get significantly easier, once you can actually interact with their enchantments. A thing to note is that Daybreak Coronet can effectively be countered if you can deal with the other Auras on the creature while it is on the stack, which means that the likes of Echoing Truth come up big here. Dedicated hosers like Chalice of the Void and Spellskite are also very strong, as is putting a lid on their white mana with Spreading Seas. If you can scratch together enough disruption, Merfolk has a quick and evasive clock to put the game away.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Spell Pierce), hand disruption (Vendilion Clique), land hate (Sea's Claim), redirect effects (Spellskite).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), slow haymakers (Master of Waves).
Burn
General Impression: Good matchup
Synopsis: Defense is the name of the game here. They're going to come out fast and furious with cheap creatures and burn spells, so your job is to preserve your life total as much as you can until you can turn the corner. Countermagic on their burn spells is generally very good (especially on effects that target both your creatures and you, like Searing Blaze or Searing Blood), Merfolk Trickster and Harbinger of the Tides (mostly when backed up by an Aether Vial) can buy time and provide bodies to either attack or trade with, Silvergill Adept trades with any creature on their side while also drawing you a card, and Master of Waves is your midgame haymaker that you're usually trying to work towards. If you are on the play or if they have a land-light hand, Spreading Seas can slow them down signifcantly and sometimes even lock them out of casting spells. Some final notes: Burn pilots occasionally play Ensnaring Bridge in their sideboard, so side in some nonland permanent bounce effects if you see it played against you. Also, be careful about blocking with Master of Waves postboard without countermagic backup: Skullcrack turns off protection's damage prevention effect.
Side in: Countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), land hate (Sea's Claim), redirect effects (Spellskite), tapdown effects (Tidebinder Mage).
Side out: Value cards (Benthic Biomancer), sorcery-speed bounce (Harbinger of the Tides).
Death & Taxes (WX)
General Impression: Good matchup
Synopsis: This Vial deck invests a lot of resources in messing with opponents' noncreature spells with effects like Thalia, Guardian of Thraben and lands with the Leonin Arbiter + Ghost Quarter 1-2 punch; unfortunately for them, Merfolk is extremely resilient to being attacked on both of those fronts. Furthermore, our creatures outmuscle theirs pretty readily when backed up by a Lord effect or two. The only real way you can run into trouble is if they manage to wall you off with Thalia and Blade Splicer effects and chip you to death with flyers like Flickerwisp and Restoration Angel. To avoid that, save your Tricksters for buying time or outright sniping flyers out of the sky. You can also potentially Harbinger them back if giving them a re-do on their enter-the-battlefield effects doesn't put you in too bad a spot. You can also use Seas effects to waltz past their blockers and crash in for the damage you need to race. Overall, this is a matchup that rewards tight play (and starting with a turn 1 Aether Vial), but more often than not we have the edge.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot).
Side out: Countermagic (Deprive, Force of Negation).
Dredgevine
General Impression: Close matchup
Synopsis: This deck is capable of some very explosive starts that can beat more or less anything, but the average hand is something you can handle, provided you draw the right mix of disruption (namely Harbinger of the Tides and Merfolk Trickster) and pressure. Master of Waves is generally a big help in this matchup, as they have few ways of removing it and it provides a large board to turn the corner with. This deck uses its graveyard quite extensively, so postboard hate will come in very handy. If you are in Game 1 or have not found your hate, you may want to have one of your Merfolk take one for the team in order to exile Bridge from Below and keep their Zombie-generating shenanigans (via Viscera Seer and/or Greater Gargadon) in check. Last but not least, watch out for a Goblin Bushwhacker putting out a bigger board than what you were equipped to handle.
Side in: Bounce (Echoing Truth), countermagic (Chalice of the Void), graveyard hate (Grafdigger's Cage, Relic of Progenitus).
Side out: Countermagic (Deprive, Force of Negation), small value creatures (Benthic Biomancer).
Eldrazi & Taxes (WBC)
General Impression: Close matchup
Synopsis: Unlike its mono-colored cousin, this deck possesses the right mix of hand disruption (Tidehollow Sculler and Thought-Knot Seer) and removal (Fatal Push, Path to Exile, and Wasteland Strangler) to actually pick apart your board synergies and clock you if left unperturbed. However, it's usually a bit of a slow starter, so stacking Lords and putting lots of boots on the ground can sometimes put them in situations where they are too far behind to come back. Alternatively, their manabase is pretty gnarly (this is effectively a 3-color deck without fetchlands), which means that a Spreading Seas on the right land can hurt them pretty badly. Master of Waves allowing you to go super wide to break board stalls can also be a big help, provided you can keep it on the battlefield. As usual in Vial pseudo-mirrors, getting the namesake artifact in your opener is a plus, and countermagic is generally unreliable.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), redirect effects (Spellskite), removal (Dismember).
Side out: Countermagic (Deprive, Force of Negation).
Elves (GX)
General Impression: Bad matchup
Synopsis: No sugarcoating it; this is a tough matchup. In order to have a chance, you need to keep their board from spiraling out of control by putting the clamps on their big mana producers (Elvish Archdruid and Heritage Druid) while effectively clocking them with a Lord-and-Seas-based offense. If you don't find that right mix, you might find yourself getting run over by Elves backed by either a mass of Lords (the Archdruid and Elvish Clancaller), Ezuri, Renegade Leader, Shaman of the Pack, or sometimes even Craterhoof Behemoth. If you do find yourself in a board state where things are more or less stable, try to counter or otherwise deal with these major payoff spells, as well as the card advantage effects (Collected Company, Lead the Stampede, and occasionally Beast Whisperer) which keep the chain moving. Again, far from an easy matchup, so you need things to break just right in order to win.
Side in: Bounce (Echoing Truth, Hibernation), countermagic (Chalice of the Void), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage).
Side out: Countermagic (Force of Negation), slow haymakers (Mater of Waves).
Faeries (UBX)
General Impression: Good matchup
Synopsis: Because this deck relies on establishing threats like Bitterblossom early and then playing a control game to back them up, you generally have a couple of turns to get a board state going before you have to worry about what they're doing. If you can get some offense going in that time, you'll find that their clock is usually a bit too slow to race you. As this is a blue deck that can put blockers in front of your attackers, getting (and keeping) Islandwalk is among your highest priorities. Keep them on the back foot (hands with Aether Vial generally have an easier time of this), interact with their planeswalkers (either on the stack or on the board), and you should win.
Side in: Bounce effects (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique).
Side out: Single-target bounce (Harbinger of the Tides), Seas effects (Spreading Seas).
Goblins
General Impression: Close matchup
Synopsis: This deck will come at you all guns blazing, so it's imperative that you put blockers in front of their attackers and slow things down until they run out of gas and you can flip the script. Preserving your life total is very important, as they have a lot of ways to push damage through. You should usually, if not always, trade cards for life if given the choice to do so. A big Master of Waves is often your best way to win here, so try and line that up as best you can. If your opponent runs Goblin Piledriver, don't forget that a Mutavault can block it, and that Dismember can kill it.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), counterspells (Chalice of the Void), redirect effects (Spellskite), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage).
Side out: Counterspells (Deprive, Spell Pierce), Seas effects (Spreading Seas).
Hollow One
General Impression: Good matchup
Synopsis: As with many of the more aggressive decks in the format, defense is the name of the game. Their big haymaker creatures (Hollow One, Tasigur, the Golden Fang, and Gurmag Angler) are vulnerable to bounce effects, so Harbinger of the Tides is very strong. They run quite a few removal spells (especially postboard), so be careful about committing to attacks that can get blown out by a single Bolt or Push. The easiest way to win this matchup is usually to weather the early storm, and work your way up to a big Master of Waves they both can't attack through and can't adequately defend against. It's also a pretty graveyard-dependent strategy, so postboard graveyard hate will do well.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), counterspells (Chalice of the Void), graveyard hate (Grafdigger's Cage, Mistcaller, Relic of Progenitus), removal (Dismember).
Side out: Value creatures (Benthic Biomancer), countermagic (Deprive), land disruption (Spreading Seas).
Humans (5c)
General Impression: Close matchup
Synopsis: As with most Vial deck pseudo-mirrors, who can establish control of the board through fast deployment and tricks has an advantage here. Hands with Aether Vial will generally perform better than ones without it. Because Humans is a bit faster but lacking in resilience, Merfolk's job is often to blunt their initial rush with Merfolk Trickster and Harbinger of the Tides, then turn the corner with Lord-stacking or by going very wide with Master of Waves. Countermagic is at its worst in this matchup, because they feature Aether Vial and Cavern of Souls to bypass it.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique, removal (Dismember, Gut Shot, tapdown effects (Tidebinder Mage), Vial hate (Mistcaller).
Side out: Countermagic (Deprive, Force of Negation).
Infect
General Impression: Close matchup
Synopsis: This is one of the fastest decks in the format, so playing defense is a must. Interactive creatures like Harbinger of the Tides and Merfolk Trickster go a long way in this matchup, as do cheap counterspells like Spell Pierce or lockdown cards like Chalice of the Void (Infect is usually well-prepared to fight through removal - counterspells are significantly harder for them to overcome). Block their creatures whenever possible, try to kill or bounce what you can't block, and then turn the corner with Lord-fueled crackbacks. Despite their having Islands to switch on your Islandwalk, you'll want to keep your Spreading Seas in postboard - it's a great answer for Inkmoth Nexus, which is otherwise one of the more annoying threats to deal with. Phyrexian mana removal spells are even better than usual here, as this deck typically won't even try to threaten your life total.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), hand disruption (Vendilion Clique), redirect effects (Spellskite), removal (Dismember, Gut Shot) tapdown effects (Tidebinder Mage).
Side out: Slow haymakers (Master of Waves), value creatures (Benthic Biomancer).
Merfolk
General Impression: Close matchup
Synopsis: The true mirror hinges heavily on two things: which player (if any) has a Turn 1 Aether Vial, and which player (if any) draws Master of the Pearl Trident (as opposed to Lord of Atlantis, whose effect applies to both players' Merfolk). Harbinger of the Tides and Merfolk Trickster have very strong blowout potential by taking Lord effects off the table and messing up combat math, and Master of Waves can be swingy (amazing if Islandwalk is not a factor on the opposing side, slow otherwise). As usual in Vial deck matchups, countermagic is poor, though perhaps worth keeping if your sideboard is low on cards to bring in.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot), Vial hate (Mistcaller).
Side out: Countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Mill (UBX)
General Impression: Good matchup
Synopsis: We have two key advantages in this matchup. First is that our reliance on basic lands and mono-colored manabase makes it very difficult for the opponent to cast Archive Traps, which buys us some time. Secondly, while they do run Ensnaring Bridge, it is not necessarily the best deck at emptying its hand and making it live. We can take advantage of that with some quick rushdown hands that provide too little time for the opponent to execute their gameplan while protecting themselves. Be judicious when playing nonbasic lands into an active Field of Ruin - you might be enabling an otherwise-dead Archive Trap or two. You should also be looking to stuff Crypt Incursion whenever possible, as that can set you too far behind to win the race.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), counterspells (Chalice of the Void, Dispel, Negate, Spell Pierce), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), redirect effects (Spellskite), tapdown effects (Tidebinder Mage).
Side out: Value creatures (Benthic Biomancer), Seas effects (Spreading Seas).
Phoenix (mono-R)
General Impression: Good matchup
Synopsis: The key to this matchup is recognizing that they are the aggressor, not you. Play defense with Harbinger of the Tides and Merfolk Trickster, then turn the corner by slamming Lords or a big Master of Waves (which they usually have no answer for). Preserve your life total as best you can - this deck is capable of some pretty explosive turns, and you'll want to either stuff them or have enough life to absorb them and either win or take control of the game. Graveyard hate shuts off Arclight Phoenix recursion as well as Bedlam Reveler, so it comes highly recommended.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Damping Sphere), counterspells (Chalice of the Void, Dispel, Spell Pierce), graveyard hate (Grafdigger's Cage, Mistcaller, Relic of Progenitus, Surgical Extraction), redirect effects (Spellskite), tapdown effects (Tidebinder Mage).
Side out: Value creatures (Benthic Biomancer), Seas effects (Spreading Seas).
Phoenix (UR)
General Impression: Good matchup
Synopsis: Despite the deck's name, I find that success in this matchup correlates most strongly with keeping Thing in the Ice under wraps. Fortunately, this deck is excellently poised to do just that, thanks to Harbinger of the Tides and Merfolk Trickster. Once you've addressed that angle, all you have to do is race their Phoenixes and Bolts, which shouldn't be too onerous a task thanks to your Lords and Master of Waves. Aether Vial obviously helps in terms of speeding up your tempo, and postboard you can bring in graveyard hate to shut down Arclight Phoenix recursion as well as some of their backup finishers like Pteramander or Pyromancer Ascension.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Damping Sphere), counterspells (Chalice of the Void, Dispel, Spell Pierce), graveyard hate (Grafdigger's Cage, Mistcaller, Relic of Progenitus, Surgical Extraction), redirect effects (Spellskite).
Side out: Value creatures (Benthic Biomancer), Seas effects (Spreading Seas).
Spirits (GUW)
General Impression: Close matchup
Synopsis: This deck is pretty close to ours in approach and abilities, with the differences being that their curve is a bit clunkier (which they make up for in part by playing more accelerants), and that their 3-color manabase gives them access to expanded tools (including the very powerful Collected Company) in exchange for taking more damage from their lands. In general, this matchup will favor whoever commits hard to the board first, but interaction on either end can lead to some big blowouts. As in other Vial matchups, countermagic is poor, but it still might be worth keeping in, as having a clean answer to Company can swing games. We have a slight edge because of our curve being a bit lower, but the fact that they run more accelerants makes it too close for us to take this matchup for granted.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), CoCo hate (Grafdigger's Cage, Mistcaller), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot).
Side out: Countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Spirits (UW)
General Impression: Good matchup
Synopsis: This deck is about as close to being Merfolk without actually being Merfolk, but they have a few weaknesses that we can pick at: most 75s have no way of generating card advantage, their creatures are a bit less aggressively inclined (so their clock tends to be a half-step slower than ours), and they have very few answers to an opponent going wide on them (which often makes an unanswered Master of Waves game-winning). Things can get a little dicey if they have an Aether Vial and you don't, but you generally have the edge if the games go according to plan. Just remember to play through your Aether Vial whenever your opponent has 3 (or more) mana open or a Vial on 3, so as to avoid Spell Queller blowouts.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot), Vial hate (Mistcaller).
Side out: Countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Amulet Titan
General Impression: Bad matchup
Synopsis: This matchup presents two major complications. First among these is that the deck is capable of some very fast hands with Primeval Titan + Amulet of Vigor, so not finding interaction in the first 2-3 turns of the game can mean that the game is over before you really get going. The second is that if you make your way to the midgame, this deck is capable of fetching some pretty problematic cards for us (Engineered Explosives and Walking Ballista) via either Trinket Mage or Tolaria West. Because of these factors, countermagic is the critical piece of interaction in order to ward off their haymakers. Cards like Merfolk Trickster can also buy you time against the Titan while clearing the way for your attackers to crash in. I have found that best results in the matchup come when the deck walks the aggro-control razor's edge. Because of this, hands with Aether Vial generally do better than ones without it. One final note is that if your opponent casts Summoner's Pact while not having the mana to pay for Spell Pierce and Primeval Titan, you should go ahead and cast the Pierce; it will cost you a card, but either force them into a suboptimal line or buy you 2 turns' worth of time.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Damping Sphere), countermagic (Ceremonious Rejection, Chalice of the Void, Dispel, Negate, Unified Will), hand disruption (Vendilion Clique), redirect effects (Spellskite), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage).
Side out: Conditional bounce (Harbinger of the Tides), conditional land hate (Spreading Seas), slow haymakers (Master of Waves).
Eldrazi Tron
General Impression: Good matchup
Synopsis: This is one of our better matchups because we can both disrupt their lands (Spreading Seas will strip a land of its types, turning off the "double mana" effect of Eldrazi Temple or the "assemble 3 lands" effect of Urza lands) and their creature payoffs (Eldrazi are not fans of Harbinger of the Tides or Merfolk Trickster). Their deck is usually a rather slow starter, so your general goal here is to put threats on the board early, then disrupt them with either interactive creatures, Seas, or countermagic to keep their big boys from getting rolling. They do have a few problematic cards in Walking Ballista, All is Dust, and postboard Ratchet Bombs, but if you can keep those under wraps, this should be a comfortable matchup for you.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Remand, Unified Will), hand disruption (Vendilion Clique), land hate (Damping Sphere, Sea's Claim, Tectonic Edge), removal (Dismember).
Side out: Slow haymakers (Master of Waves), value creatures (Benthic Biomancer).
Scapeshift (RGX)
General Impression: Close matchup
Synopsis: The name of the game here is to kill them before they can attack with Primeval Titan or cast Scapeshift for lethal. There are several ways you can go about this. One of them is to curve out aggressively and counter stabilization tools like Anger of the Gods. Another is to play the aggro-control route and gradually commit to the board while countering ramp spells and payoffs alike. A harder-to-execute but more powerful third approach is to cut them off green mana with Spreading Seas, which can happen if they get a bit greedy fetching basic Mountains. One final note is that if your opponent casts Summoner's Pact while not having the mana to pay for Spell Pierce and Primeval Titan, you should go ahead and cast the Pierce; it will cost you a card, but either force them into a suboptimal line or buy you 2 turns' worth of time. Before the printing of Merfolk Trickster and the advent of maindecking counterspells like Deprive, I would have considered this matchup to be bad for Merfolk; however, these advances have gone a long way in giving us a fighting chance.
Side in: Bounce (Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique), land hate (Sea's Claim, Tectonic Edge), tapdown effects (Tidebinder Mage).
Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Tron (GX)
General Impression: Close matchup
Synopsis: While Tron is undeniably a powerful deck, and they have haymakers that can give us a ton of trouble (Oblivion Stone, Ugin, the Spirit Dragon, Walking Ballista, and Ulamog, the Ceaseless Hunger to a lesser extent), we are fortunate enough to have a fast clock to pressure them with and the maindeck ability to interact with Urza lands (Spreading Seas will strip a land of its types, turning off the "assemble 3 lands" effect until they find another copy). Depending on the contents of your hand, you'll be looking to either go pedal-to-the-metal and get them to 0 before the haymakers land, slap a Seas on their lands and take them to 0 before they can reassemble Tron, or play like a supersized Delver deck by getting early threats down and then holding up countermagic to ensure they reach the finish line. We also have access to a plethora of sideboard cards that perform well in the matchup. When taking the Seas approach, watch out for O-Stone and Nature's Claim interrupting your plans. Overall, this multiplicity of feasible approaches to winning the game gives us a bit of an edge, but Tron is too inherently powerful a strategy to take winning for granted.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Chalice of the Void, Dispel, Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique), land hate (Damping Sphere, Sea's Claim, Tectonic Edge).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), slow haymakers (Master of Waves).
Tron (UX)
General Impression: Good matchup
Synopsis: I find this to be one of our best matchups in the entire Modern format. Their principal ways of buying time to assemble the Urza lands (bounce and countermagic) are generally poor against an Aether Vial deck, and we feature a fast clock, disruption for their Urza lands, and unblockability to complicate matters further. While there are some haymakers you will want to interact with if possible (Oblivion Stone, Ugin, the Spirit Dragon, Walking Ballista), the best results in this matchup generally come from curving out and pressuring their life total quickly with a bit of disruption in the midgame to ensure you stay ahead on board. This is a matchup in which tempo matters much more than card advantage, so prioritize speed and aggressiveness.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Pithing Needle, Sorcerous Spyglass), countermagic (Ceremonious Rejection, Dispel, Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique), land hate (Damping Sphere, Tectonic Edge).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), slow haymakers (Master of Waves).
Ad Nauseam
General Impression: Close matchup
Synopsis: This matchup is all about executing the aggro-control gameplan; you're going to want to find enough of a clock to threaten a T4/5 kill, but also enough countermagic to fend off a T4 kill attempt on their end. The main spells I recommend expending resources on countering are Ad Nauseam and Phyrexian Unlife, but ramp artifacts like Lotus Bloom and Pentad Prism are worth countering if you see that your opponent is missing land drops or if it provides them with just enough mana to go off. Bouncing their Phyrexian Unlife when they're at negative life or redirecting a Lightning Storm kill attempt to Kira, Great Glass-Spinner are some alternative (and cool) ways to win. If your opponent casts a Laboratory Maniac on a non-combo turn, be prepared to bounce it or counter a spell by their next upkeep; they're very likely setting up a kill with it, Angel's Grace/Unlife, and Spoils of the Vault (by naming a card that isn't in their deck).
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Damping Sphere, Kira, Great Glass-Spinner), countermagic (Ceremonious Rejection, Chalice of the Void, Dispel, Negate, Remand, Spell Pierce, Unified Will), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Devoted/Vizier Company (GWX)
General Impression: Bad matchup
Synopsis: Our struggles in this matchup largely stem from their speed (their fast hands can threaten to go off with infinite G plus the payoff of their choice as early as Turn 3) and our interaction package lining up somewhat awkwardly against a deck whose combo pieces are creatures (the permanent removal effects blue has access to are limited, to say the least). In order to win this matchup, you'll have to find the right mix of disruptive effects that actually impact the matchup, and use them to back up your early pressure. Tempo-type effects such as bounce and Merfolk Trickster should target the Devoted Druid above all, as the opponent has to untap with it in order for the infinite-mana combo it forms with Vizier of Remedies to truly be complete.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), combo hate (Mistcaller, Pithing Needle, Sorcerous Spyglass), countermagic (Dispel, Negate, Remand), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Cique), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage).
Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Dredge
General Impression: Good matchup
Synopsis: Merfolk is one of the few decks that lines up well natively against the graveyard menace. We have disruptive creatures to buy time against their recursive threats, Spreading Seas can cut them off the RR they need for Conflagrate, shut down their Life from the Loam engine, or ward off Darkblast, and Master of Waves is a card they have few productive answers to. Furthermore, we have access to some good graveyard hate postboard. When to pull the trigger on a mass exile effect like Relic of Progenitus depends on the card that you're trying to beat. If you are trying to stop them from recurring creatures or draining you with a Creeping Chill, you can afford to be patient, as all of those abilities use the stack and can be responded to. That is not the case for Conflagrate, Darkblast, or Life from the Loam, and you should exile those on sight.
Side in: Bounce (Echoing Truth), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), creature protection (Kira, Great Glass-Spinner).
Side out: Conditional disruption (Merfolk Trickster), countermagic (Deprive), small value creatures (Benthic Biomancer).
Gifts Storm
General Impression: Close matchup
Synopsis: Game 1 against this opponent can be rough, as we have relatively few answers to their gameplan in the maindeck. You generally have to try and line up your maindeck counterspells with their cost reducers (Baral, Chief of Compliance and Goblin Electromancer) or Gifts Ungiven. Alternatively, Merfolk Trickster shuts off their cost-reducing effect, so an aggressive hand paired with some Tricksters on upkeep can stall them long enough for you to get there. Postboard, we have a significantly better shot at keeping them under wraps, as graveyard hate and extra countermagic hurt them quite a bit. Remember to bring in some bounce effects for Empty the Warrens, as that is the main way they will try to navigate around hate. My recommendation in this matchup is to not tap out on your turn past Turn 2 or so if you can avoid it - their deck is very explosive, and letting them do as they please for even one turn can spell doom.
Side in: Bounce (Echoing Truth), combo hate (Damping Sphere), countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), graveyard hate (Grafdigger's Cage, Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Clique), removal (Dismember).
Side out: Conditional bounce (Harbinger of the Tides), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Grishoalbrand
General Impression: Good matchup
Synopsis: The way we do well in this matchup is by developing the board early, then holding up interaction for any of their ways to attempt to kill you. Countermagic and graveyard hate address Goryo's Vengeance into Griselbrand; the backup win conditions (Through the Breaching in Emrakul, the Aeons Torn or Worldspine Wurm) can be addressed by Merfolk Trickster or Harbinger of the Tides. The rest of the Fish are there to provide pressure, and Vial ensures you don't have to choose between holding up disruption or applying pressure. As this is a heavily graveyard-dependent deck, you'll want to bring in your hate for this one.
Side in: Bounce (Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Remand, Spell Pierce), graveyard hate (Grafdigger's Cage, Mistcaller, Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Clique).
Side out: Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Living End (BRG)
General Impression: Good matchup
Synopsis: There are two approaches to be taken in this matchup. First among these is trying to deny them the ability to resolve their namesake spell. For that, you'll need a mix of countermagic and pressure to ensure that Living End never turns the tables on you (along with the occasional Spreading Seas to cut them off a color). A second approach (typically employed when one's hand is light on countermagic) is to mitigate the damage the spell will actually do. Tools often used for this purpose are deploying creatures at instant speed, as well as ways to deal with the fatties this deck dumps into the graveyard (either by exiling them as they hit the bin, or dealing with them once they're on the battlefield). Chief among the ones you must find an answer for is Archfiend of Ifnir, as that cycle effect is bad news for a go-wide deck. Overall, though, we feature the right mix of aggressive and interaction to give this deck fits. When lining up permission for postboard Living Ends, bear in mind that Ricochet Trap may be lurking.
Side in: Bounce (Venser, Shaper Savant), countermagic (Chalice of the Void,Negate, Remand, Spell Pierce), graveyard hate (Mistcaller, Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), small value creatures (Benthic Biomancer).
Living End (UR)
General Impression: Good matchup
Synopsis: This matchup mostly revolves around not letting their money spells (As Foretold and Electrodominance, which in turn enable Ancestral Vision and Living End) to resolve, and if they do, to manage the ensuing damage as well as possible. The former is typically accomplished by a combination of pressure and countermagic, while the latter can be achieved by hate and playing around boardwipe mana. Be prepared for the occasional counter war when facing this deck - Remand and Cryptic Command means they won't always take your attempts to counter their spells laying down.
Side in: Bounce (Venser, Shaper Savant), countermagic (Chalice of the Void,Negate, Remand, Spell Pierce), graveyard hate (Mistcaller, Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Azorius Control
General Impression: Good matchup
Synopsis: This matchup sometimes gives newer Merfolk players a bit of trouble, but I believe we have a notable edge once you learn the ropes. Generally, you're trying to keep value engines (such as the planeswalkers, Cryptic Command, Snapcaster Mage, Search for Azcanta, and sweepers like Supreme Verdict and Terminus) from running you out of resources. You can accomplish this with countermagic of your own, by killing the 'walkers as soon as they hit the field, or by leveraging manlands for offense to minimize the effect of sweepers. Unlike in most U-centric matchups, Spreading Seas is worth keeping around postboard, as many of the ways this deck is trying to beat you revolve around lands. Don't waste precious resources dealing with things our deck is inherently built to battle through (such as Path to Exile on non-critical creatures or a Timely Reinforcements you can islandwalk around), and you will do well.
Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster).
Blue Moon
General Impression: Good matchup
Synopsis: This deck comes in two major flavors: the combo varieties use things like Madcap Experiment into Platinum Emperion, Deceiver Exarch plus Kiki-Jiki, Mirror Breaker, and Through the Breach into Emrakul, the Aeons Torn to win games, whereas the "pure control" varieties focus harder on card advantage and try to win eventually via Snapcaster Mage, Thing in the Ice, Vendilion Clique, and occasionally Pia and Kiran Nalaar. What version you are facing influences whether cards such as Merfolk Trickster (which is pretty good against the combo versions) should make the postboard cut. Regardless of what version you're facing, the general approach is similar: deploy aggressively early, weather the initial removal spells, and try to leverage your interaction to win races in the mid-to-lategame. Master of Waves is a card this deck struggles mightily to answer, so centering your gameplan around sticking him with a decent amount of devotion is a good way to win games. This deck generally relies heavily on countermagic and land hate to slow its opponents down, which does little against a deck with lots of basic Islands and Aether Vial. They also don't feature enough spot removal to put a major dent in your plan. You have a pretty convincing edge in this matchup.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Jeskai Control
General Impression: Close matchup
Synopsis: While Merfolk generally doesn't mind facing a bit of spot removal, this deck has enough of it to actually pose a challenge to your gameplan. To counteract that, you need to break from the classic "don't over-commit" control gameplan a bit and get on the board aggressively. Being able to get your guys out of Bolt range (while not easy) is a major boon, as it invalidates a big chunk of their spot removal. This tactic is less likely to get punished than against other control opponents, as they tend to run fewer sweepers, especially in Game 1. As usual against a U-based deck, play through your Aether Vial to avoid countermagic and sorcery-speed effects, counter planeswalkers and other value engines when you can, and beware the Snapcaster Mage-into-removal line wiping your board.
Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Pyro Prison
General Impression: Close matchup
Synopsis: This matchup revolves around Ensnaring Bridge - in Game 1, you need to counter it or kill your opponent before they find it and empty their hand enough to lock out your offense. Postboard, you bring in your answers and can thus answer an active Bridge lock. Other annoying cards to watch for are Chandra, Torch of Defiance and Anger of the Gods. The Rabblemaster plan (Goblin Rabblemaster and Legion Warboss) is typically not that much of a threat, since Merfolk is readily capable of putting bodies in front of the tokens, or trade with the token generators themselves. As long as you can keep the Bridge angle under control, you should win.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Sultai Reclamation Control
General Impression: Good matchup
Synopsis: The main thing to watch out for out of this matchup is that the deck is primarily composed of instants, and cards like Consume the Meek can be a beating if they catch you unprepared. However, this deck is generally a bit light on removal density, instead relying on Wilderness Reclamation to double up its turn-by-turn mana production and on Mystical Teachings to find whatever it may need. Disrupt that engine, and you will find that the deck is often too slow to threaten you. Alternatively, put together a fast aggro start, and they may take too long to get set up. Postboard, you can bring in some more disruption for their gameplan to keep things running smoothly. Because this deck is mostly focused on spell-slinging, most of your interaction points will be on the stack or in the graveyard. Regardless, most Merfolk decks should have a comfortable edge in this matchup.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Grafdigger's Cage, Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Whir Prison
General Impression: Bad matchup
Synopsis: This deck is able to get an Ensnaring Bridge quickly, reliably, and then protect it in a variety of ways, which makes it a pretty challenging matchup for us. The key to getting there in this matchup is to start aggressively - you're going to want to curve out in the first 2-3 turns of the game, and either threaten a Turn 4 kill or have some countermagic to hold up in the midgame (and ideally, you want to have both those things going on). Chalice of the Void on 2 turns off most of our deck, and Engineered Explosives on 2 blows most of it up, so those are cards you may be forced to interact with in order to win. If you do counter the Bridge, bear in mind that they feature tools to either get another copy (Inventors' Fair, Whir of Invention) or to fish it out of the graveyard (Academy Ruins), so don't take too long to finish the game, or they will re-establish their lock. Not a good matchup, but certain hands feature the right combination of disruption and pressure to win.
Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Abzan
General Impression: Close matchup
Synopsis: While most BGX decks are similar to each other from our perspective, this one has one particularity to note in that it features a go-wide angle in Lingering Souls. These tokens are rarely much of a threat in their own right, but they can buy your opponent time as blockers and generally muck up the battlefield if you don't happen to have a Seas effect. Furthermore, their reliance on W and B for their removal means you can't quite lean as heavily on Master of Waves as you would in other midrange matchups. Apart from that, the standard advice applies: fight through their discard and removal by presenting a constant stream of threats, don't mulligan if you can avoid it, mess with their manabase using Spreading Seas, pressure their life total hard if they have an active Dark Confidant, and try to clear any Liliana as soon as she hits the battlefiddddeld. Handling their other threats with bounce, Trickster, or postboard graveyard hate also comes highly recommended.
Side in: Bounce (Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage).
Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation).
Eldrazi Stompy (mono-C)
General Impression: Close matchup
Synopsis: This matchup often comes down to who can sustain their pressure from the early game to the midgame. While Eldrazi tends to be a fast starter thanks to being willing to dig for double-mana Eldrazi Temples and the like using Serum Powder or aggressive mulligans, all that tearing through the deck can sometimes leave your opponent light on gas. That means that if you can weather the initial wave of Thought-Knot Seers and Reality Smashers that are popping out ahead of schedule by either disrupting them, getting on board faster than them, or slowing them back down with Spreading Seas, you'll be in a great spot to flip the script on your opponent. I recommend trading off or disrupting Eldrazi Mimic early (as it can otherwise have an outsize impact for what is effectively a 1-drop in many Eldrazi hands) and not trading with Eternal Scourge or Matter Reshaper if at all possible. Last but not least, watch out for Chalice of the Void or postboard Ratchet Bombs on 2, especially if you don't have an Aether Vial.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Remand), hand disruption (Vendilion Clique), removal (Dismember).
Side out: Countermagic (Deprive, Force of Negation), value creatures (Benthic Biomancer).
Grixis Shadow
General Impression: Good matchup
Synopsis: The more controlling of the Shadow variants, this deck has two major weaknesses to our deck: it relies heavily on U (so it switches on islandwalk for us without any effort required), and it hacks away at its own life total to leverage some of its powerful cards, such as Death's Shadow (which means you have to sneak through significantly less damage to win). It also has a postboard weakness in that graveyard hate is quite good against it, as the graveyard fuels both Gurmag Angler and Snapcaster Mage. To win this matchup, you generally want to put pressure on them to develop their board (which usually involves them damaging themselves) while simultaneously having to deal with removing your threats. Next, you can either skip past their blockers with islandwalking hordes, or disrupt their big individual threats with the likes of Harbinger of the Tides and Merfolk Trickster. You'll generally have to weather some discard spells and removal to pull this off, but that's something Merfolk is well-equipped to do. Last but not least, beware the Temur Battle Rage, as that is one of the main ways this deck can steal games from you and your blockers.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), graveyard (Relic of Progenitus), hand disruption (Vendilion Clique), land hate (Sea's Claim), removal (Dismember), removal protection (Kira, Great Glass-Spinner).
Side out: Accelerants (Aether Vial), countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Jund
General Impression: Close matchup
Synopsis: The most historically common of the BGX decks, Jund is a matchup where inexperienced Merfolk players sometimes struggle, but seasoned pilots have a markedly easier time with. The key to it is to keep them on the back foot with a constant stream of threats that they must answer, and thus keeping them from mounting an offense of their own. Because of this, Silvergill Adept is often your best card in the matchup, as it is a card they must answer that gets you another card. That said, because of Jund's reliance on R for its removal spells, Master of Waves is also quite good. Mulliganing is also something I only recommend you do if your hand is truly non-functional, as you need as many resources as you can scrounge up at your disposal. Disrupting their attempts to start an offense also comes highly recommended, so lining up Merfolk Trickster with Tarmogoyf, putting a lid on Raging Ravine with Spreading Seas, walling Bloodbraid Elf with blockers, resetting Scavenging Oozes with bounce, or killing any Liliana planeswalker on sight are all very good things to be doing. Postboard, you should also bring in graveyard hate to aid you in keep their threats manageable. Lastly, if faced with an active Dark Confidant without a reliable means to take it off the battlefield, commit hard to pressuring their life total - they do some amount of damage to themselves with fetches, shocks, and Thoughtseize, so turning their life total against them can help you walk away with wins where your opponent is way ahead on cards.
Side in: Bounce (Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage).
Side out: Accelerants (Aether Vial), condition bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation).
Mardu Pyromancer
General Impression: Close matchup
Synopsis: This midrange deck's particularities are that it has a go-wide threat dimension composed of Young Pyromancer tokens and Spirits from Lingering Souls, and that it can generate big chunks of card advantage by slowing the game to a standstill then slamming Bedlam Revelers to refill its hand. Because of these angles of attack, postboard graveyard hate plays a big role in the matchup. Because this deck leans heavily on R for both threats and removal, Master of Waves is an absolute beating, and can sometimes win games more or less on its own. Apart from that, your standard attrition gameplan applies: don't mulligan if you can avoid it, present a constant stream of threats, try to disrupt their threats whenever you can, and prioritize cards that let you do those things while replacing themselves (such as Silvergill Adept and Spreading Seas).
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage).
Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive).
Ponza (RGX)
General Impression: Good matchup
Synopsis: One of our best matchups in Modern, this deck attacks an axis we are well-prepared to defend. Blood Moon and Stone Rain don't do much against a deck with lots of basic lands and Aether Vial, and their mostly R-based threats and removal line up pretty poorly against a Master of Waves. Hitting a land with Utopia Sprawl on it with Spreading Seas is also a nasty blowout, as the Utopia Sprawl will no longer be legally enchanting that land and will thus fall off. Your goal here should be to start pumping out threats, disrupt their mana acceleration (or answer their threats with countermagic, bounce, or tapdown effects), and beat them down before they can recover. My experience is that Merfolk is exceedingly good at executing this gameplan against Ponza, and thus wins the matchup quite often.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Remand), hand disruption (Vendilion Clique), land hate (Sea's Claim), tapdown effects (Tidebinder Mage).
Side out: Conditional bounce (Harbinger of the Tides), value creatures (Benthic Biomancer).
The Rock (BG)
General Impression: Close matchup
Synopsis: A relative newcomer to the BGX lineup, this one features Field of Ruins to attack your Mutavaults, a less painful manabase to mitigate the bad side of Dark Confidant, and Kalitas, Traitor of Ghet as a nasty top-end threat. A strategy I've sometimes employed to good effect is to cut them off colors by relying on basic lands to cast my spells (thus stranding the Fields) and slapping Spreading Seas on their remaining lands (especially if they are dual lands). Directing your creature interaction toward Kalitas will also help keep him under wraps. Apart from this, the standard BGX advice applies: fight through their discard and removal by presenting a constant stream of threats, don't mulligan if you can avoid it, pressure their life total hard if they have an active Dark Confidant, and try to clear any Liliana as soon as she hits the battlefield. Handling Scavenging Ooze and Tarmogoyf with bounce, Trickster, or postboard graveyard hate also comes highly recommended.
Side in: Bounce (Venser, Shaper Savant), graveyard (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage).
Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation).
Traverse Shadow
General Impression: Good matchup
Synopsis: The more aggressive of the Shadow variants, this deck still hacks away too hard at its own life total to have a good Merfolk matchup. It also has little use for U, so Spreading Seas can often be quite painful. Still, this deck can pose a threat by powering out undercosted beaters in Death's Shadow and Tarmogoyf, so have your creature disruption at the ready. Patience is key in this matchup - let them damage themselves to enable their gameplan while you develop your board, and then proceed to disrupting them while simultaneously upping the pressure. Postboard graveyard hate hits this deck very hard, so it comes highly recommended. As long as you can keep yourself from being overwhelmed by undercosted fatties or having a game snatched from under you by a Temur Battle Rage, you are a strong favorite to win.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), graveyard (Relic of Progenitus), hand disruption (Vendilion Clique), land hate (Sea's Claim), removal protection (Kira, Great Glass-Spinner).
Side out: Accelerants (Aether Vial), countermagic (Deprive, Force of Negation).
Fringe Decks:
Delver (URX)
General Impression: Good matchup
Synopsis: There are two basic types of Delver decks in Modern. One variety is the spell-heavy decks that add B or G to the mix and pair Delver of Secrets with complementary threats such as Tarmogoyf and Hooting Mandrills or Gurmag Angler and Tasigur, the Golden Fang. The other is a more tribal-style strategy that employs the likes of Vendilion Clique and Nimble Obstructionist as additional threats. Our approach to both versions is similar - they tend to have quite a bit of spot removal and Snapcaster Mages to run it back, so you'll need to weather that and interact with their threats as you take over the board and chip down their life total. Harbinger of the Tides tends to be especially valuable here, as many of their threats require setup. Lords are also quite strong, as the nature of these decks' construction means islandwalk is pretty much always on. Aether Vial also helps quite a bit here, as it can help you deploy faster and allows you to dodge countermagic. Lastly, most of these decks struggle to interact with Master of Waves, so he's a great haymaker to work your way up to. As long as you can keep them on the back foot (and most of the time, you can), you have a marked edge.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Remand), flyers (Kira, Great Glass-Spinner, Vendilion Clique), graveyard hate (Relic of Progenitus), removal (Dismember, Gut Shot).
Side out: Seas effects (Spreading Seas).
Eldrazi (RGC)
General Impression: Close matchup
Synopsis: This matchup is usually a good old-fashioned race: can your Lord-stacking get to the finish line before their large, hasty threats? Because of this goal, you generally want to see a bunch of Lords, and supplement them with a bit of disruption. Your creatures are usually cheaper, so try to get boots on the ground first and establish a life lead. They play a decent amount of spot removal, so be careful about getting blown out in combat by something like a Bolt on your Lord. Lastly, be careful about running out a Master of Waves without countermagic backup or a second copy already in play - Eldrazi Obligator's additional effect is colorless in nature, and they can use it to steal your Master and kill your tokens.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Remand), hand disruption (Vendilion Clique), land hate (Sea's Claim, Tectonic Edge), removal (Dismember).
Side out: Value creatures (Benthic Biomancer).
Eternal Command
General Impression: Good matchup
Synopsis: This deck's primary goal is to set up an Eternal Witness + Aether Vial + Cryptic Command loop to counter the first spell an opponent plays every turn. Needless to say, this takes a bit too long to truly be effective against Merfolk, and the resulting effect is not that strong against us either. Their plan B usually involves a graveyard-based value game involving removal spells, Scavenging Ooze, Snapcaster Mage, and Tarmogoyf. Because they gift you islandwalk by nature of their manabase and our ability to bring in postboard graveyard hate, this plan is also unlikely to stop you. Get on the battlefield early, pressure their life total, and save some disruption for their any loop pieces or attempts to stabilize, and you'll do well.
Side in: Countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique), removal (Dismember).
Side out: Seas effects (Spreading Seas).
Hatebears (WG)
General Impression: Good matchup
Synopsis: This deck is looking to punish certain types of game actions, such as countermagic, discard, noncreature spell-spamming, and searching one's library for cards, while pressuring them with creatures such as Thalia, Guardian of Thraben and Leonin Arbiter. You'll note that none of those effects are all that common in Merfolk, and thanks to Lord-stacking, our creatures tend to be larger. Because of this, the matchup tends to be pretty favorable. Things you do want to watch out for are big creatures like Wilt-Leaf Liege (which allows them to do some Lord-stacking of their own) and Loxodon Smiter coming down ahead of schedule thanks to mana dorks like Noble Hierarch. Put boots on the ground in the early game, save some disruption (especially board disruption) for their big guys, and you'll do fine.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot).
Side out: Countermagic (Deprive, Force of Negation), small value creatures (Benthic Biomancer).
Soul Sisters
General Impression: Close matchup
Synopsis: There is some variation in the exact decklists for this archetype: some are mono-W decks that lean on the likes of Honor of the Pure, Ajani's Pridemate, Squadron Hawk, and Spectral Procession to close out games, while others splash R for Norin the Wary and lean heavily on Human synergies via Champion of the Parish and Thalia's Lieutenant. Regardless of what version you face, the gameplan is the same: you want to build up a bigger board state than theirs, then use Seas effects to punch through their defenses and hack through their lifegain while disruptive creatures keep their threats off you. Bear in mind that the Sisters themselves (Soul Warden, Soul's Attendant, and occasionally Auriok Champion) can also attack and block, so keep blockers back to prevent chip damage and gobble them up with combat tricks if you are presented with an opportunity to do so.
Side in: Bounce (Echoing Truth), countermagic (Chalice of the Void), removal (Dismember, Gut Shot).
Side out: Go-wide haymakers (Master of Waves), countermagic (Force of Negation), small value creatures (Benthic Biomancer).
Zoo (Bushwhacker)
General Impression: Close matchup
Synopsis: This is a pretty fast all-in aggro deck, so you'll need some of Merfolk's defensive resources at your disposal in the early game to stem the early tide of creatures, especially if they get haste from a Reckless Bushwhacker. You should also watch out for Atarka's Command messing up your combat math. Once you stem the offensive tide with Harbinger of the Tides and/or Merfolk Trickster, Master of Waves is often the best way to flip the script on them. Alternatively, they have a pretty color-intensive deck combined with a fragile manabase, so Spreading Seas can sometimes pull a lot of weight here. The general gist of the matchup is that the longer the game goes, the better it is for you.
Side in: Bounce (Echoing Truth), countermagic (Chalice of the Void, Dispel), land hate (Sea's Claim), redirect effects (Spellskite), tapdown effects (Tidebinder Mage).
Side out: Countermagic (Deprive, Force of Negation), small value creatures (Benthic Biomancer).
Zoo (Classic)
General Impression: Good matchup
Synopsis: This deck is similar to ours in that it seeks to back up mid-size creatures with a bit of disruption, but they present several weaknesses in the head-to-head contest in a painful manabase that doesn't have much use for U (so Spreading Seas is strong in the matchup), some sensitivity to graveyard hate (via Knight of the Reliquary, Scavenging Ooze, and Tarmogoyf), and a clunkier curve with lots of 3-drops and only a nominal amount of mana acceleration. Because of this, we generally get our pressure going first, can cut them off colors while enabling our unblockability, and can disrupt them while further developing our battlefield. We can even outmuscle them, if our draw has enough Lords. They do run a fair amount of spot removal (especially postboard), so be careful when attacking into their creatures.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), flyers (Kira, Great Glass-Spinner, Vendilion Clique), land hate (Sea's Claim), removal (Dismember), tapdown effects (Tidebinder Mage).
Side out: Small value creatures (Benthic Biomancer).
Devotion (GX)
General Impression: Good matchup
Synopsis: This deck's goal is to combine effects that untap lands on creatures (namely Arbor Elf) and planeswalkers (Garruk Wildspeaker) with enchantments such as Utopia Sprawl or with Nykthos, Shrine to Nyx to make tons of mana and ramp out powerful expensive spells. Your primary goal should be to interact with that gameplan as much as possible while also pressuring their life total. Fortunately, you have many tools to help you accomplish this goal. Spreading Seas deals with Utopia Sprawl while also drawing you a card and enabling islandwalk. Merfolk Trickster and Harbinger of the Tides can help you slow down their creature-based ramp, and your aggro game can help get Garruk off the table as soon as he hits. Furthermore, some of the haymakers the deck puts out just aren't that scary to Merfolk - the likes of Hornet Queen can be circumvented via islandwalk, for example. As long as you're getting a healthy mix of disruption and pressure, this is a matchup you should win.
Side in: Bounce (Echoing Truth, Hibernation, Venser, Shaper Savant), countermagic (Remand), hand disruption (Vendilion Clique), land hate (Sea's Claim), removal (Dismember, Gut Shot), tapdown effects (Tidebinder Mage).
Side out: Slow haymakers (Master of Waves).
Scapeshift (UGX)
General Impression: Good matchup
Synopsis: These decks are usually running what amounts to a ramp-control gameplan until they have enough lands to threaten an instant kill with Scapeshift. As such, you have two avenues to victory - one is to threaten them with a resilient aggro game and ignore the ramp aspect (because you're hoping to kill them before they have Scapeshift mana); the other is to interact with them as best you can and hope incidental pressure carries the day. Either is effective (though I have found the aggressive one to be a bit more so), and which one you opt for usually depends on your draw. Fortunately for us, the fact that we don't take damage from our manabase effectively buys us an extra turn against their primary win condition, which usually gives us the time we need to scratch together enough damage to cross the finish line first. Watch out for sweepers (especially if the opponent is on the 4/5-color Bring to Light variant) and postboard backup plans like Madcap Experiment into Platinum Emperion, and you should be fine.
Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique), land hate (Tectonic Edge).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Cheeri0s
General Impression: Close matchup
Synopsis: This matchup hinges entirely on wehther you can scratch together enough interaction to allow your beatdown plan to finish the game. Their win condition, while inconsistent, is blazing fast, so you must be prepared to interact in order to win. Going for their card draw engines (Puresteel Paladin and Sram, Master Edificer) or locking them out of casting 0-drops with Chalice are the safest routes, but occasionally countering the likes of Retract will cause them to stall out. As you do that, build up your board, pressure them aggressively, and hopefully it's enough.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Spell Pierce), hand disruption (Vendilion Clique), removal (Dismember).
Side out: Conditional bounce (Harbinger of the Tides), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Jeskai Ascendancy
General Impression: Close matchup
Synopsis: Your goal here is typically to catch the namesake Jeskai Ascendancy enchantment on the stack, and then beat your opponent to death with your Merfolk while they dig for a new one. Alternatively, interacting with their win conditions (usually a Fatestitcher, though some versions also play G for access to mana-producing creatures instead) can also buy you some time. The key thing to keep in mind is that you must develop your gameplan quickly: this deck is mostly composed of cantrips, so the deck will find what it needs if given enough time. That said, this also means that they usually cannot spare much deck space to interacting with their opponents, so the straightforward rushdown is pretty effective against them.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Spell Pierce), hand disruption (Vendilion Clique), removal (Dismember, Gut Shot).
Side out: Conditional bounce (Harbinger of the Tides), Seas effects (Spreading Seas), slow haymakers (Master of Waves)
Neoform Combo
General Impression: Good matchup
Synopsis: This very fast glass-cannon combo deck is built around cheating a Griselbrand into play using Allosaurus Rider combined with either Eldritch Evolution or the namesake Neoform. Once it's done that, it will draw its entire deck with Nourishing Shoals, then finish you off with either Lightning Storm or Laboratory Maniac. Thankfully, Merfolk has access to the bane of this deck's existence in countermagic. Mulliganing aggressively for interaction comes recommended here, as the deck quite literally does nothing if their combo attempt is halted. Dig for your counterspells, stuff their gameplan, and a concession will likely follow.
Side in: Activated ability hate (Pithing Needle, Sorcerous Spyglass), bounce (Venser, Shaper Savant), combo hate (Grafdigger's Cage, Mistcaller), countermagic (Dispel, Negate, Remand, Spell Pierce), hand hate (Vendilion Clique).
Side out: Expensive haymakers (Master of Waves),Seas effects (Spreading Seas)
Restore Balance
General Impression: Close matchup
Synopsis: The effects of the namesake spell resolving are typically devastating for a creature deck like Merfolk, so your gameplan revolves areound making sure it doesn't. With that said, don't neglect your ability to apply pressure; they will eventually force a way past their defenses if you give them enough time. Interacting with the Borderposts that they use for mana in lieu of lands is highly recommended. Lastly, don't lose sight of the fact that most iterations of this deck can threaten the combo at instant speed through either Electrodominance and Violent Outburst, so try not to tap out in the midgame if you can avoid it. This matchup clearly gets easier with the more permission you run.
Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Saheeli/Copycat Combo
General Impression: Good matchup
Synopsis: There are two major iterations of this deck. One of them uses a Jeskai midrange shell, with notable amounts of spot removal and cantrips; the other is a G-based 4-color deck that tries to assemble the necessary mana a bit faster with the likes of Birds of Paradise and Lotus Cobra, then generates consistency with tutor effects such as Eldritch Evolution. Either variant brings the threat of a value midrange game (featuring lots of enters-the-battlefield effects to rebuy with Felidar Guardian) while the combo is being assembled, but both of them usually grant you islandwalk in the process of casting their spells, which is a nice boon. The combo itself is easy enough for us to interact with; deal with either the Felidar or with Saheeli Rai, and the music stops. This combination of circumstances make this a matchup Merfolk is well-suited to winning.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand), hand disruption (Vendilion Clique), removal (Dismember), tutor hate (Grafdigger's Cage).
Side out: Conditional bounce (Harbinger of the Tides), Seas efects (Spreading Seas), slow haymakers (Master of Waves).
Thopter Sword (UBX)
General Impression: Close matchup
Synopsis: Unlike most creature decks, Merfolk is able to slip through a mass of Thopter tokens should the Sword of the Meek + Thopter Foundry combo get assembled (especially since this deck will give you the islandwalk for free, as most of its non-artifact spells are U-based), so that occurrence is not game over for us. This gives us game in the matchup that other decks cannot boast. However, your goal should be to drop your opponent before they manage to assemble these pieces. Ensnaring Bridge is usually present in these decks, so plan your sideboarding accordingly. Interact with the Foundry on the stack if you can - hand disruption and Spellskite will make it significantly more difficult once it's on the table. Other than that, proritize pressure and try to get them low before they assemble the combo, such that they need something other than the combo to bail them out.
Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus, Surgical Extraction), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Turns (UX)
General Impression: Close matchup
Synopsis: While this deck has access to some annoying ways to punch through your defenses in Exhaustion and Gigadrowse, the plan to develop your board early and hold up countermagic as you clock them is something this deck is quite weak to. Deal with their extra draw engines (Dictate of Kruphix, Jace, the Mind Sculptor, and occasionally Howling Mine or Ancestral Vision) if you get a chance - this makes it much harder for them to find the resources to attempt to go off, and to sustain the chain once they being to do so. Prioritize hands that have fast starts - your goal should be to threaten lethal by the time they've begun to set up, or at the very least to have a counterspell and a clock.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Dispel, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Vannifar "Pod" Combo
General Impression: Close matchup
Synopsis: While creature-based combo decks typically give Merfolk a bit of trouble, this one throws us a few bones in that its main combo piece costs 4 mana (which gives us enough time to set up countermagic), requires U to be cast (which means we sometimes get islandwalk for free), and that our disruptive Merfolk are effective speedbumps against it (an instant-speed Harbinger of the Tides or a Merfolk Trickster will both buy you a turn). With that in mind, you have a reasonable chance of putting together the mix of disruption and pressure you need to win this game. Bear in mind that Prime Speaker Vannifar is there to fetch the winning combo (typically Kiki-Jiki, Mirror Breaker combined with some way to untap it), not be the win condition herself; if the game goes long enough, they can draw into the combo naturally.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Negate), graveyard hate (Grafdigger's Cage, Relic of Progenitus), hand disruption (Vendilion Clique), removal (Dismember), tapdown effects (Tidebinder Mage).
Side out: Seas effects (Spreading Seas), slow haymakers (Master of Waves).
8-Rack
General Impression: Close matchup
Synopsis: While this is a discard-based attrition deck, Aether Vial is actually pretty handy here, as they usually play some amount of land destruction, sometimes have sorcery-speed sweepers, and extra copies can be held to weaken the effects of Wrench Mind. You'll also want to take the draw in any postboard games where you get the choice in the matter; resources are of paramount importance in the matchup. Generally, you want to try and establish a strong board presence early, and get stuff out of your hand before it gets picked off by targeted discard. Once The Rack and/or Shrieking Affliction are on the table, you should reverse course and attempt to hoard as many cards in your hand as possible, unless casting those cards would allow you to outrace their effects or they have a recurring discard outlet, such as Liliana of the Veil or Raven's Crime. Lastly, this deck sometimes packs Ensnaring Bridge, so plan accordingly.
Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Emeria Titan
General Impression: Good matchup
Synopsis: This is a slow value deck that grants you islandwalk for free and is somewhat light on interaction, all of which combines to make it easy prey for us. Get Lords on the table, protect them with countermagic, and rush them down without fear. If you do, their deck philosophy of buying time with blockers and lifegain until they can run their opponent out of resources is unlikely to work on you. Watch out for the occasional Supreme Verdict, try to counter their Sun Titans, bring in your postboard graveyard hate, and keep your Seas postboard (evasion is paramount, and shutting off Emeria, the Sky Ruin can be useful in longer games).
Side in: Bounce (Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Esper Control
General Impression: Good matchup
Synopsis: While this control deck has a deep suite of spot removal and card advantage tools, it is very slow to turn the corner, which affords you lots of time to mount an offense, recover from disruption, and keep chipping away. They will usually feature some amount of sweepers, so be careful not to over-extend into them. One way to do that is to play through your Aether Vial, which has the additional benefit of avoiding their countermagic. Countering or otherwize limiting card advantage engines such as Teferi, Hero of Dominaria is one of the best ways to deal with these types of opponents. As long as you stay disciplined and keep the gas flowing, this should be a matchup you win quite often.
Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Grixis Control
General Impression: Good matchup
Synopsis: While this is a control deck, it mostly relies on spot removal to hold the fort in the early game, and thus you can be aggressive with your creature deployment and force them to deal with lots of threats at once. Lord-stacking is quite important here, as it helps you get out of range of Lightning Bolt and Kolaghan's Command. Despite being vulnerable to that card, Aether Vial is very handy here, as it helps you deploy more quickly and avoid their countermagic. Graveyard hate is especially effective here, as many of their threats and value mechanisms rely on it. Our combination of unblockable pressure and disruption is typically pretty hard to overcome, so Merfolk enjoys a marked edge.
Side in: Bounce (Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Lantern Control
General Impression: Bad matchup
Synopsis: Arguably the worst matchup for Modern Merfolk. Their ability to quickly slap down Ensnaring Bridge and dump its hand makes it very challenging for us to mount an offense, and it can pick off our limited ways to deal with said Bridge with discard spells and mill effects such as Codex Shredder combined with Lantern of Insight. To top it off, the deck has Ancient Stirrings, Inventors' Fair, and Whir of Invention to help it dig for what it needs. Your best chance here is to catch the Bridge coming in and clock them before they can find another, Chalice them out of their 1-drops and eventually find an answer for Bridge, or to knock their life total low before they apply the lock and sneak through the final points after dealing with the Bridge for a turn. Unfortunately, my experience is that this is highly unlikely.
Side in: Bounce (Echoing Truth, Hurkyl's Recall, Venser, Shaper Savant), countermagic (Ceremonious Rejection, Chalice of the Void, Negate, Spell Pierce), graveyard hate (Relic of Progenitus), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas), slow haymakers (Master of Waves).
Martyr Proc
General Impression: Close matchup
Synopsis: There are two things to watch out for in this matchup; you don't want to get got by a pumped-up Serra Ascendant, and you don't want to get ground out by value loops of Squadron Hawk, Martyr of Sands, and Ranger of Eos backed up by removal and other ways to stymie your offense. Merfolk Trickster is the cleanest answer to Ascendant, though Harbinger of the Tides coupled with some pressure will do in a pinch. Countermagic is the best remedy for the latter strategy, though postboard graveyard hate can also be helpful.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Chalice of the Void, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique).
Side out: Conditional bounce (Harbinger of the Tides), slow haymakers (Master of Waves).
Skred Red
General Impression: Good matchup
Synopsis: This deck has a good amount of removal to slow you down, but its combination of vulnerability to countermagic (due to its reliance on big, expensive threats) and its general inability to deal with a resolved Master of Waves make us a pretty convincing favorite. Getting your threats out of range of Anger of the Gods and Lightning Bolt range is also a massive boon, though you should take care to not get blown out by a souped-up Skred. Strategy-wise, your goal is to exert constant pressure on your opponents, forcing them to expend resources holding you off. When a threat hits the table, you should attack it if it's a planeswalker, or interact with it if it's a creature. If you cannot interact with it, redouble your efforts to protect your own creatures - chances are that you can win a race, if it comes to that.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Dispel, Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique), removal (Dismember).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas).
Sun & Moon
General Impression: Good matchup
Synopsis: While this is a prison deck, some of its lock pieces (Blood Moon and Chalice of the Void on 1) are pretty ineffective against us, which combines with a clunky manabase to give us a marked edge in the matchup. Kill their planeswalkers on sight, play around sweepers by deploying creatures at instant speed with Aether Vial, and keep chipping away at their life total, and your opponent will likely capitulate. They may feature Ensnaring Bridge, so be sure to bring in your postboard answers to that card.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), hand disruption (Vendilion Clique).
Side out: Creature interaction (Harbinger of the Tides, Merfolk Trickster), Seas effects (Spreading Seas)
Sultai
General Impression: Good matchup
Synopsis: This deck is similar in configuration to other BGX midrange decks, but presents us with one major advantage: its usage of U means they provide us with Islands, often rendering their creatures unable to block. Because of this, the matchup has a markedly more positive spin than its cousins. Apart from this, the standard BGX advice applies: fight through their discard and removal by presenting a constant stream of threats, don't mulligan if you can avoid it, pressure their life total hard if they have an active Dark Confidant, and try to clear any Liliana as soon as she hits the battlefield. Handling Scavenging Ooze and Tarmogoyf with bounce, Trickster, or postboard graveyard hate also comes highly recommended.
Side in: Bounce (Venser, Shaper Savant), graveyard hate (Relic of Progenitus), land hate (Sea's Claim, Tectonic Edge), removal (Dismember), removal protection (Kira, Great Glass-Spinner), tapdown effects (Tidebinder Mage).
Side out: Accelerants (Aether Vial), conditional bounce (Harbinger of the Tides), countermagic (Deprive, Force of Negation), Seas effects (Spreading Seas).
Tokens (WBX)
General Impression: Good matchup
Synopsis: The key to winning this matchup usually involves assembling the combination of islandwalk and Spreading Seas. Your task is to put that together through their spot removal and discard, and to do so quickly enough to outrace their flyers and pump effects. Fortunately, they're usually a pretty slow starter, so you'll have quite a bit of time to get things going and beat them to the spot. Alternatively, you can set up for a big Master of Waves, and beat them at their own go-wide game. An important part of the matchup is to address their value engines - Bitterblossom is usually not the biggest deal, but any planeswalker should be countered or taken down as soon as possible. Postboard, mass bounce effects tend to be crippling, as they are often one-sided boardwipes. This is a matchup in which you enjoy a significant speed advantage.
Side in: Bounce (Echoing Truth, Venser, Shaper Savant), countermagic (Negate, Remand, Spell Pierce), graveyard hate (Relic of Progenitus).
Side out: Accelerants (Aether Vial), creature interaction (Harbinger of the Tides, Merfolk Trickster).
4 Aether Vial
Creatures (28)
4 Benthic Biomancer
4 Harbinger of the Tides
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Merfolk Trickster
4 Merrow Reejerey
4 Silvergill Adept
4 Spreading Seas
Instants (4)
4 Force of Negation
Lands (20)
10 Island
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
4 Waterlogged Grove
3 Deprive
2 Dismember
2 Echoing Truth
4 Leyline of the Void
2 Phyrexian Revoker
2 Venser, Shaper Savant
4 Aether Vial
Creatures (28)
4 Kumena's Speaker
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Merfolk Mistbinder
4 Merfolk Trickster
4 Merrow Reejerey
4 Silvergill Adept
4 Spreading Seas
Instants (4)
4 Force of Negation
Lands (20)
4 Botanical Sanctum
2 Breeding Pool
2 Flooded Strand
4 Island
4 Mutavault
4 Waterlogged Grove
2 Collector Ouphe
4 Deprive
2 Dismember
2 Echoing Truth
2 Reclamation Sage
3 Relic of Progenitus
3 Aether Vial
Creatures (28)
4 Benthic Biomancer
2 Cursecatcher
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Merfolk Trickster
4 Merrow Reejerey
2 Mistcaller
4 Silvergill Adept
4 Cryptic Command
2 Spell Pierce
2 Vapor Snag
Lands (21)
18 Island
2 Mutavault
1 Oboro, Palace in the Clouds
2 Dismember
4 Hurkyl's Recall
4 Relic of Progenitus
1 Surgical Extraction
4 Wizard's Retort
4 Aether Vial
Creatures (26)
4 Benthic Biomancer
2 Harbinger of the Tides
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
4 Merfolk Trickster
4 Silvergill Adept
4 Spreading Seas
Instants (6)
4 Deprive
2 Spell Pierce
Lands (20)
14 Island
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
2 Dismember
2 Echoing Truth
2 Grafdigger's Cage
4 Relic of Progenitus
1 Spell Pierce
2 Tidebinder Mage
2 Wizard's Retort
4 Aether Vial
Creatures (20)
4 Harbinger of the Tides
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Merfolk Trickster
4 Silvergill Adept
Enchantments (4)
4 Spreading Seas
4 Deprive
4 Dismember
4 Repeal
Lands (20)
4 Faerie Conclave
11 Island
4 Mutavault
1 Oboro, Palace in the Clouds
4 Chalice of the Void
3 Echoing Truth
4 Relic of Progenitus
4 Tectonic Edge
4 Aether Vial
2 Smuggler's Copter
Creatures (27)
4 Cursecatcher
3 Harbinger of the Tides
4 Lord of Atlantis
4 Master of the Pearl Trident
3 Master of Waves
3 Merrow Reejerey
4 Silvergill Adept
2 Vendilion Clique
4 Spreading Seas
Instants (3)
3 Dismember
Lands (20)
2 Cavern of Souls
12 Island
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
3 Ceremonious Rejection
2 Dispel
1 Echoing Truth
2 Hurkyl's Recall
2 Negate
3 Relic of Progenitus
2 Unified Will
4 Aether Vial
Creatures (29)
4 Cursecatcher
3 Harbinger of the Tides
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
3 Merrow Reejerey
4 Silvergill Adept
1 Tidebinder Mage
2 Vendilion Clique
4 Spreading Seas
Instants (3)
3 Dismember
Lands (20)
2 Cavern of Souls
12 Island
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
3 Dispel
2 Relic of Progenitus
4 Tectonic Edge
2 Tidebinder Mage
4 Unified Will
4 Aether Vial
1 Relic of Progenitus
Creatures (27)
4 Cursecatcher
2 Kira, Great Glass-Spinner
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
3 Merrow Reejerey
1 Phantasmal Image
4 Silvergill Adept
1 Tidebinder Mage
4 Spreading Seas
Instants (4)
3 Dismember
1 Vapor Snag
Lands (20)
2 Cavern of Souls
12 Island
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
2 Gut Shot
4 Hurkyl's Recall
2 Relic of Progenitus
2 Spell Pierce
4 Tectonic Edge
1 Tidebinder Mage
4 Aether Vial
Creatures (33)
4 Cursecatcher
4 Harbinger of the Tides
1 Kira, Great Glass-Spinner
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
4 Merrow Reejerey
4 Phantasmal Image
4 Silvergill Adept
4 Spreading Seas
Lands (19)
2 Cavern of Souls
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
10 Island
1 Wanderwine Hub
2 Dismember
2 Echoing Truth
4 Hurkyl's Recall
1 Negate
2 Relic of Progenitus
2 Tidebinder Mage
2 Unified Will
4 Aether Vial
Creatures (29)
4 Cursecatcher
4 Harbinger of the Tides
2 Kira, Great Glass-Spinner
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
3 Merrow Reejerey
4 Silvergill Adept
4 Spreading Seas
Instants (4)
2 Dismember
2 Spell Pierce
Lands (19)
2 Cavern of Souls
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
9 Island
2 Wanderwine Hub
1 Dismember
2 Dispel
3 Hurkyl's Recall
1 Negate
2 Relic of Progenitus
2 Spellskite
2 Tidebinder Mage
2 Unified Will
4 Aether Vial
Creatures (31)
4 Cursecatcher
4 Harbinger of the Tides
1 Kira, Great Glass-Spinner
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
4 Merrow Reejerey
2 Phantasmal Image
4 Silvergill Adept
4 Spreading Seas
Instants (1)
1 Vapor Snag
Lands (20)
3 Cavern of Souls
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
11 Island
1 Dismember
4 Hurkyl's Recall
2 Relic of Progenitus
2 Remand
2 Spell Pierce
2 Spellskite
2 Vapor Snag
4 Aether Vial
2 Relic of Progenitus
Creatures (25)
4 Cursecatcher
4 Lord of Atlantis
4 Master of the Pearl Trident
3 Master of Waves
3 Merrow Reejerey
4 Silvergill Adept
3 Tidebinder Mage
4 Spreading Seas
Instants (5)
3 Dismember
2 Vapor Snag
Lands (20)
1 Cavern of Souls
1 Minamo, School at Water's Edge
4 Mutavault
1 Oboro, Palace in the Clouds
10 Island
3 Wanderwine Hub
1 Dispel
2 Hibernation
1 Kira, Great Glass-Spinner
2 Master of Waves
2 Remand
3 Spell Pierce
4 Tectonic Edge
1 Tidebinder Mage
4 Benthic Biomancer
4 Harbinger of the Tides
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Master of Waves
4 Merfolk Trickster
4 Silvergill Adept
4 Spreading Seas
Instants (6)
4 Deprive
2 Spell Pierce
Lands (22)
20 Island
2 Tectonic Edge
2 Ceremonious Rejection
2 Dismember
4 Echoing Truth
3 Relic of Progenitus
2 Spell Pierce
2 Tectonic Edge
This is what a typical mono-U Modern Merfolk core looks like:
Modern Merfolk Deck Skeleton:
Artifacts (4-8)
4 Aether Vial
0-4 Flex Slots
Creatures (20-33)
4 Lord of Atlantis
4 Master of the Pearl Trident
4 Silvergill Adept
8-21 Flex Slots
Enchantments (0-8)
0-4 Spreading Seas
0-4 Flex Slots
Instants (4-12)
4 Force of Negation
0-8 Flex Slots
Lands (18-20)
4 Island
0-4 Mutavault
14-16 Flex Slots
Modern Merfolk Core Cards:
These cards are the core of the Modern Merfolk deck:
Aether Vial – This is our tempo anchor. It gives you the ability to spit out creatures faster than you could otherwise cast them, and adds to your interaction ability by flashing your creatures in response to your opponent’s spells or even as a combat trick. They can be a bit of dead topdeck (which is why they tend to come out against decks with an attrition gameplan), but in general it is one of your most important cards. In fact, it's so important, that it gets its own section, as described below.
Force of Negation – An absolutely incredible spell for Merfolk. This lets you both develop your board and protect yourself from whatever your opponent has going on in the early game, and can quite easily be cast using its normal mana cost in the mid-to-late game. Because the vast majority of cards in this deck are blue, you'll rarely be lacking for fodder to feed it, and its tempo boost can be the difference between a win and a loss. I consider it an essential part of the Modern Merfolk toolbox.
Island – They help you cast your dudes and your spells. Boring, but effective.
Lord of Atlantis – One of the major reasons to play this deck. Global pump and evasion along with a 2/2 body are a heck of a deal for UU, and it gets only scarier in multiples. Just be careful when playing the mirror – he pumps your opponent’s guys, too.
Master of the Pearl Trident – The remixed version of Lord of Atlantis, this one has the perk of being strictly beneficial. Don’t leave home without it.
Mutavault – This useful little land gives us another body to project all of our tribal buffs onto (including that of Master of Waves), and it has the benefits of being cheap to activate, colorless (so it can dodge effects meant for U creatures, such as protection), and that it dodges sorcery-speed or nonland permanent removal spells. Another note is that you can sandbag its activation during the combat phase to try and dodge effects such as Cryptic Command, but beware of what you say when entering combat - otherwise, you may find yourself in situations like this one. The fact that it doesn't produce U can sometimes be a bit problematic, but it's a problem we're well-equipped to deal with thanks to Aether Vial. A staple in this deck, and for good reason.
Silvergill Adept – This guy gives us a nice body to project our pump effects on as well as another card. His drawback rarely comes up given our deck’s typical creature count, and it keeps the engine running smoothly. Along with the Lords, this card's existence is what makes Merfolk a thing.
Spreading Seas – One of our sneaky-good tempo pieces, this card fulfills multiple roles in our deck. It grants our creatures evasion when one of our Lords is on the table, it can disrupt your opponent’s mana base, and it replaces itself to boot. A bit hit-or-miss against most decks that already run U, but very potent in general.
This section will focus on cards that have been proven to be successful complements to the Merfolk core cards shown above. If it's not on this list, it's likely a budget alternative (see the section below), or it's just not that good in Merfolk. I'm also marking the choices with a tag that should clarify whether a card is generally thought to be mainboard or sideboard-playable (and in some cases, both).
Artifacts:
Chalice of the Void – This is a very potent tool to bring in against opponents who rely heavily on 0-drops (such as Affinity, Cheeri0s, or Living End) or 1-drops (Bogles, Burn, Death's Shadow, Elves, Infect, GX Tron, and Phoenix). It can be a bit clunky on the draw, and it's not the greatest topdeck, but its early game shutdown potential makes it worth running. Whether it forms part of your mainboard or your sideboard depends on the expected metagame. Mainboard or Sideboard
Damping Sphere – If you expect to face big mana decks like Amulet and Tron, pure spell-spam decks like Phoenix and Storm, or any other deck looking to slam multiple spells in a turn or cheat on mana production, this will be a very potent tool in your sideboard arsenal. While it won't lock your opponent out of the game altogether, it will slow them down significantly, and Vial ensures it likely will not do the same to us. Sideboard
Grafdigger's Cage – This handy little artifact puts a damper on everything from conventional graveyard reanimation decks to Snapcaster Mage triggers to cards like Chord of Calling and Collected Company. Not truly applicable enough to be featured in the mainboard, but it's a potent sideboard bullet that can really make some matchups (notably Company decks, reanimator decks, and any combo deck relying on tutors or the graveyard) less troublesome. Sideboard
Pithing Needle – While this card requires some knowledge of the inner workings of your opponent's deck to be of optimal use, it can be a cheap answer to a lot of problematic permanents that doesn't interfere with your curve. At its best when brought in from the sideboard once you know what you're playing against. Sideboard
Relic of Progenitus – Probably the best piece of graveyard hate for Merfolk. It’s cheap to cast, and it can either whittle away at the ‘yard to keep your opponent from mining it for value, or it can clean it out in response to a combo or any other dangerous play. And it cantrips on top of all of that. Highly recommended as a sideboard piece to bring against combo, control, and midrange decks, and in some metagames it's even mainboard-playable. Mainboard or Sideboard
Sorcerous Spyglass – This card is narrow, but it eliminates some of the guesswork involved in naming a specific card by giving you a chance to peek at your opponent's hand first. The inherent value of information is hard to quantify, but what is clear is that it's helpful to have, and this card's main effect can shut down annoying effects, especially from opposing combo pieces. Sideboard
Creatures:
Benthic Biomancer – While a cheap creature with what is usually a one-time loot effect may not seem impressive in a vacuum, Merfolk is a deck that makes very good use of those effects in the mid-to-late game, as extra copies of Aether Vial or lands beyond what you need to cast your spells are essentially dead cards. Getting that effect in addition to a 1-drop that can also help you curve out and be aggressive is quite handy, especially considering that it permanently pumps itself in the process. Mainboard
Coralhelm Commander – While this card won't be winning any races, it provides several effects we crave in flying and the ability to pump the team. It makes for a quality mana sink, which is something many versions of Merfolk lack. It takes a particular kind of Merfolk 75 to make this good, but it's very good if you do have the right conditions for it. Mainboard
Cursecatcher – While it seems a bit unassuming at first, this card can be a helpful tempo piece against combo decks looking to go over the top on you early and removal-heavy decks that are trying to kill your more dangerous Merfolk. Furthermore, it can serve as early pressure until its effect is called upon. This kind of flexibility and disruptive capability is always welcome in a tempo deck like Merfolk. Mainboard
Harbinger of the Tides – One of the most potent disruptive Merfolk we have access to. Its bounce effect combined with a relevant body can be a huge tempo swing in our favor, and its flash option makes it even more flexible. Additionally, it has great synergy with Merrow Reejerey (tap an opponent’s creature on casting, bounce the creature with Harbinger's enters-the-battlefield ability) and Merfolk Trickster (tap a creature on your opponent's turn, bounce it on your turn). Mainboard
Kira, Great Glass-Spinner – One of the nicer tricks in the Merfolk toolbox, Kira helps keep your creatures safe against targeted removal in addition to providing an emergency flying attacker/blocker. Not being a Merfolk and costing 3 mana (including 2 U symbols) are real downsides, but it’s something that you can work around. Good in either the main or the side. Mainboard or Sideboard
Kopala, Warden of Waves – A handy little 3-drop that helps protect our team while benefiting from all of our tribal synergies. While a tax effect is generally not considered to be as powerful as Kira's counterspell effect, it has very good synergy with cards like Cursecatcher and Spell Pierce, and is unique among the protection effects we have available in that it can ward off uncounterable kill spells like Rending Volley and Abrupt Decay (at least for a time). That combined with the fact that he can get pretty big in this deck thanks to the Lord effects have made him a welcome addition to the Merfolk toolbox. Mainboard
Master of Waves – This is the deck’s haymaker. Protection from R and CMC4 means it shrugs off a lot of common removal spells, and its enters-the-battlefield token-generating effect often creates insurmountable board states (or protects you from whatever your opponent has going on). Not the greatest against fast combo decks, but excellent otherwise, and highly recommended. Mainboard
Merfolk Trickster – Tapping a creature and removing its abilities is quality interaction, and getting a flash Merfolk body is just icing on the cake. This is a very powerful catch-all creature, and likely to become a part of Modern Merfolk's core in the near future. Mainboard
Merrow Reejerey – Another Lord effect, should you need it. While its effect isn’t as offensively potent as the 2-mana Lords, it’s a very versatile one. You can use it as pseudo-ramp by untapping your own lands or Aether Vials, as evasion by tapping your opponent’s creatures, or defensively by untapping your Fish after an attack. A very flexible and useful card. Mainboard
Mistcaller – While this little guy's effect is conditional, it's often quite a blowout when it does come to pass. It's relevant against reanimator decks like Dredge and Grishoalbrand, creature-combo decks with cards like Chord of Calling, Collected Company, Eldritch Evolution, and Neoform and it can be used to delay Aether Vial activations (just bear in mind that the Vial's controller can choose to not use the artifact after you activate it), and it's a cheap Merfolk body to project your buffs on against the rest of the field. It can definitely shine in the right metagame. Mainboard or Sideboard
Phantasmal Image – This card can be very flexible in that you can either copy your own creatures to get more of an effect you wanted (be it pump, card draw, tokens, or disruption), or something cool that your opponent is doing (especially if you'd have a hard time responding to it otherwise). However, it is very fragile (it can die to something as innocuous as a pump spell or a tap effect). Moreover, most of our traditional ways to protect creatures (counterspells, Kira, Great Glass-Spinner, Spellskite) can’t save it. It's also worth noting that it's not a Merfolk while in your hand or being cast, so it interacts poorly with Cavern of Souls, Merrow Reejerey, Silvergill Adept, or Wanderwine Hub. It can be very powerful, but it has to be used judiciously. Mainboard
Phyrexian Revoker – Mostly analogous to a Pithing Needle effect, this one offers some additional upside on our end by virtue of being a creature. That means that you can use Aether Vial to flash it in while a palatable target for its effect is on the stack, and that it can attack your opponent. Furthermore, our deep suite of dangerous creature threats makes the opponent’s choice on what creature to use spot removal on more difficult. Lastly, while this card cannot affect the likes of utility lands, it can affect mana abilities on nonland permanents. This can be quite important, and makes the Revoker quite versatile in what kind of permanents it can answer. Sideboard
Spellskite – This card is interesting in that it can be used both offensively as disruption to decks that rely on targeted effects (such as Aura Hexproof/Bogles, Burn, Infect, and UR Prowess), or defensively to soak up damage-based removal. It’s not much to look at in terms of pressure (I'd suggest looking at it as a noncreature spell when determining how many threats are in your deck), but it can help protect your pressure as it takes down your opponent. At its best as a sideboard bullet, where it can dodge artifact hate and only come in to ruin your opponent's day. Sideboard
Thassa, God of the Sea – Scrying every turn before you draw can be a potent advantage, and getting to devotion 5 (note that it counts itself for this purpose, as well as cards like Spreading Seas) gives you access to a powerful indestructible beatstick. Unblockability for 1U can also be handy in situations where your islandwalk isn't live. While 3 mana is a bit on the expensive side, I consider it to be helpful in avoiding Merfolk's main internal issue in flooding, and thus worthy of seeing play. An important thing to keep in mind is that indestructible does not save this creature from dying to Dismember or Path to Exile when it is in creature form. Mainboard
Tidebinder Mage – This card’s effect is narrow enough that it belongs in the sideboard in most metagames, but it makes for one heck of a sideboard card. Tapping your opponent’s creature down indefinitely is oftentimes as good as removing it (and sometimes it's even better), and you get a body of a relevant type as a bonus. Sideboard
Vendilion Clique – While this card is not a Merfolk and is also a bit tricky in terms of mana cost, it fills a need by being a flier with an aggressive body and having a disruptive enter-the-battlefield effect. Very potent if you're expecting big mana, all-in combo decks, and sweepers. Mainboard or Sideboard
Venser, Shaper Savant – This guy is on the expensive side (and isn't a Merfolk), but it offers a truly unique tempo effect capable of doing things no other card can (e.g. bouncing Supreme Verdict to buy your rush one more turn). The fact that it brings a 2/2 body along can't be ignored, either. His best application is as a sideboard haymaker to decks vulnerable to this sort of tempo-intensive play, and he's good at that role. Sideboard
Enchantments:
Sea's Claim – This card can combine with Spreading Seas to basically shut your opponent out of their lands if they’re not running U. Not terribly useful against U-based decks (though we’re typically favored against those anyway), but it can be devastating to any deck relying on a 3-color manabase or otherwise depend heavily on their lands (BGX, Burn, Death's Shadow, Eldrazi, Tron, and Zoo, for example). My recommendation for this card is to run it in the sideboard and bring it in where it can be most effective, but it has also been employed in the mainboard to good effect. Mainboard or Sideboard
Instants:
Ceremonious Rejection – A very cheap and efficient tool with which to stymie the likes of Affinity, Eldrazi, and Tron decks. It's a bit narrow and can be shut off by the likes of Cavern of Souls, but it's crazy good if you manage to connect with it. I think that this card can be a viable substitute for Merfolk's more traditional land hate sideboard package, and thus should play a prominent role in the sideboards that choose to feature it. Sideboard
Deprive – While it is not always trivial to come up with the UU to cast this card, countering any spell with no conditions other than returning a land (which Aether Vial and a low curve can make less of an issue) is very powerful. A great catchall piece of interaction that can put in good work in either the mainboard or the sideboard. Mainboard or Sideboard
Dismember – Probably the best removal spell we have access to by default. It can be sometimes be painful to cast, but hard removal against most relevant creatures in Modern is worth the pain. Merfolk players have used this in both the mainboard and the sideboard, depending on what the metagame context dictates. Mainboard or Sideboard
Dispel – Narrow, but cheap and effective at disrupting a lot of spells that you don't want to resolve, like Collected Company, Cryptic Command, Electrolyze, Gifts Ungiven, Goryo's Vengeance, Kolaghan's Command, Searing Blaze, Through the Breach, and many other examples. Almost strictly a sideboard card, but it's good at that role. Sideboard
Echoing Truth – A nice catchall bounce effect, its ability to bounce copies can come up big against tokens and other decks that like multiples of a same effect on the board (including the mirror match). A strong card that I recommend for the great majority of Merfolk 75s, and some metagames even dictate that this be a maindeck inclusion. Mainboard or Sideboard
Gut Shot – It doesn’t look like much at first glance, but this can provide you with a potent early tempo advantage by zapping small creatures (especially mana dorks like Arbor Elf, Birds of Paradise, or Noble Hierarch) at the cost of a bit of life. Definitely playable in your sideboard, even if it's not the flashiest. Sideboard
Hibernation – A great hoser out of the sideboard, this card comes up huge against the likes of Aura Hexproof/Bogles, Elves, and Zoo, flipping tempo in your favor. However, it’s a bit up there in terms of mana cost, so it can be a bit awkward to cast at times. Sideboard
Hurkyl's Recall – A mass bounce effect for one of the permanent types that we need it most. It can be a life-saver against the likes of Affinity, 8-Rack, Lantern Control, and Whir Prison out of the sideboard. Sideboard
Negate – A very effective and versatile counterspell, especially against big-mana decks like Tron and Valakut that can just pay the extra cost imposed by a card like Spell Pierce. A strong sideboard card. Sideboard
Remand – While it doesn’t get rid of whatever it targets permanently, the tempo boost you get from sending it back up to their hand makes it worth your while, especially given that you get to draw a card afterwards. I think that it fits in well with our primary gameplan, and can play an important role in either the main or the side. Mainboard or Sideboard
Spell Pierce – A great catchall counterspell for most things Merfolk doesn’t want to see resolved, it also has the benefit of being cheap and easy to sneak into a curve. Not the most individually potent card, but its flexibility and speed are major assets. Mainboard or Sideboard
Unified Will – As a creature-based tempo deck, Merfolk will often have more boots on the ground than its opponent, and that makes this a powerful hard counter to bring in out of your sideboard at a reasonable mana cost. At its best against combo or control decks, where there are important spells to counter and few bodies to interfere with its ability. Sideboard
Vapor Snag – Bouncing a creature is a nice tempo play, and tacking on a life loss effect on top of it makes it even nicer. You can even use it to save your own creatures in case of an emergency. I think it's an integral piece of our disruption package, and is thus mainboard-worthy. Mainboard
Lands:
Cavern of Souls – Makes your Merfolk uncounterable, which is a nice perk to have against control and opposing tempo decks. However, it has a notable downside in that it can only produce U for your Merfolk, which can sometimes complicate the business of casting creatures while leaving mana up for interaction purposes, or casting some of our useful toolbox creatures. Because of this, most players that play this card opt for less than the full playset. Even with this drawback, the effect is strong enough to be worth considering. Mainboard
Faerie Conclave – Not exactly the first thing that springs to mind when you think "Merfolk", but it's a land that produces U (check), can make good use of your excess mana (double check), and can turn into a flying attacker or blocker (triple check). It requires a bit of maneuvering in order to use effectively, but it has proven to be a handy part of the Merfolk arsenal. Mainboard
Fiery Islet/Waterlogged Grove – These lands produce U, and can be cashed in for a card if you have excess lands. This sort of effect is very useful in Merfolk, which doesn’t have that many mana sinks, and also has Aether Vial to help with its mana production requirements. Very handy cards. Mainboard
Minamo, School at Water's Edge – It protects you from Boil, Choke, and giving up islandwalk in the mirror match. It can also be a sneaky on-board trick if you happen to have a legendary creature on the battlefield (and we run those on occasion). Most Merfolk manabases can and should make room for it. Mainboard
Oboro, Palace in the Clouds – This is Boil/Choke/mirror protection, and it has a sneaky-good interaction with any of your C-producing lands when you're short on land drops, but really need U mana (tap Oboro for U, tap any other land for the 1 to bounce Oboro, replay Oboro and tap for U). Last but not least, you can beam it back up to your hand if you need to discard a card for something like a Benthic Biomancer's adapt ability or a Liliana of the Veil activation. Highly recommended as a mainboard 1-of. Mainboard
Tectonic Edge – This is one of Merfolk players' preferred pieces of land hate. It's uncounterable by virtue of being a land, works at card parity, hits a wide variety of targets (shocklands, manlands, Tron lands, Eldrazi Temple, Valakut, the Molten Pinnacle, etc.), and it's relatively inexpensive to use. Bringing this card in from your sideboard can really ruin some opponents' days. Sideboard
Wanderwine Hub – This card gives you U while keeping you safe from the likes of Boil, Choke, and enabling islandwalk in the mirror, and it even gives you W if you're into that sort of thing. The tapland drawback is basically negligible in a tribal deck like ours, which makes it a fine choice. Mainboard
This is an addendum to the Preferred Card Choices section, and contains cards that haven't put up much in the way of concrete and notable results, but could be interesting additions to the deck. Try these out at your own risk, and be sure to report back on how they do!
Artifacts
Sentinel Totem – A similar card to Relic of Progenitus, except it downgrades the ability to replace itself to a scry 1 in exchange for not needing to hold up mana in order to wipe the graveyard. Should you feel that the mana needed to babysit Relic is holding you back in certain matchups, this could be a palatable alternative.
Smuggler's Copter – While this card has power and toughness values, it's best to think of it as a utility boost to any one of your creatures - it can enable you to get damage in on board states where you otherwise wouldn't (for example, in a ground stall where you don't have islandwalk), and the flying can be valuable on the defensive end. Furthermore, the looting effect is quite handy at smoothing out some of our clunkier draws. A handy little card to have. Mainboard
Creatures
Cosi's Trickster – Likely the most aggressive 1-drop we have access to as Merfolk, this one can take advantage of your opponent using effects like fetchlands, or shuffles forced by your own effects (Ghost Quarter, for example) to grow pretty big. Mainboard
Mothdust Changeling – This guy is interesting because it provides an ability Merfolk finds hard to come by (flying). Unfortunately, you have to tap a creature to get it, which is not ideal. Still, it has some potential as a 1-drop if you find that you really need early-game flyers. Mainboard
Skaab Ruinator – An interesting option in removal-heavy matchups, its large size and ability to self-recur are undeniable assets in a drawn-out game. It also can be Vialed in to remove its initial casting requirement. It's not a Merfolk and it doesn't help your team beyond being big (which are real strikes against it), but it still has some potential. Sideboard
Tideshaper Mystic – While it doesn't quite disable lands the way Spreading Seas can, having a creature that can switch on islandwalk and help you force damage through when needed is still a pretty handy thing to have. An interesting experimental option. Mainboard
Watertrap Weaver – Don't be fooled by the somewhat unassuming base stats; this card is a beating against virtually any opposing creature deck by virtue of its ability, and the fact that it's a Merfolk means it can get pumped to the point where it is a threat. A bit overshadowed by Merfolk Trickster, but available shoud you want additional copies of the tapdown effect. Mainboard
Enchantments
Deeproot Waters – While this card is very slow (as it does not affect the board when it enters the battlefield) and somewhat at odds with Aether Vial (as it requires that you actually cast your Merfolk), it has some potential as a substitute for the Vial in attrition matchups. Flooding the board with hexproof Merfolk can really be a thorn in the side of midrange and control decks, particularly when they have some Lord effects to back them up. A card to consider. Sideboard
Monastery Siege – This card is pretty versatile, but it’s a bit on the slow side. Both of the modes can help you against attrition-based decks (and the Dragons mode is pretty good against the likes of BGX, Grixis, and Burn), but it's a very awkward play in a hand where you don’t draw Aether Vial. It could be helpful, but the extent of how much is somewhat questionable. I think it's strictly a sideboard card. Sideboard
Threads of Disloyalty – A bit off the beaten path, this nonetheless offers a powerful effect. Taking control of the likes of Death's Shadow, or Tarmogoyf, or other undercosted beater can really turn a game around, and if an opponent has no enchantment hate, they might be forced to remove their own creature, adding insult to injury (not to mention provide you with card advantage). Its range is narrow enough that I can't justify it in the mainboard, but it's a potent sideboard effect. Sideboard
Instants
Cryptic Command – While expensive and hard to cast, this card's raw power and flexibility is undeniable. It can interact with the opponent on the stack or on the board, and usually replace itself to boot. If you're looking for an off-the-beaten-path inclusion for Merfolk's top end, perhaps this is worth a try. Mainboard
Disdainful Stroke – If you're looking to defend against cards like Primeval Titan, Collected Company, and pretty much anything that matters out of Eldrazi or Tron, this card is a strong option. It's also very strong against control decks, since many of their midgame haymakers are within range. Worth some consideration. Sideboard
Disrupting Shoal – While certainly unorthodox, this counterspell has some potential in Merfolk, given that this is a mono-colored deck with cards at a variety of different mana costs to pitch to it (especially for x=2, which is a popular mana cost for opponent's spells) and it also helps free up your mana to develop your board and still keep shields up. It's unproven, but it could be very powerful. Mainboard
Flashfreeze – While narrow, this counterspell catches a lot of very potent spells, ranging from sweepers like Pyroclasm and Anger of the Gods to game-winning effects such as Primeval Titan and Scapeshift. If you don't want to let a problematic spell resolve, this seems like a strong option. Sideboard
Mana Leak – A decent counterspell. Its "tax" effect combined with its 2 CMC means it won't always be live, but it's plenty powerful when it is. Its catchall nature makes it a good mainboard inclusion for those inclined to test it, but I wouldn't recommend it as a sideboard card. Mainboard
Peek – While information is inherently valuable, the exact impact of it is hard to quantify. This currently offers you a good amount of that, while being cheap and replacing itself. If you're in the market for seeing what your opponent is up to, this is likely the best rate currently available in mono-blue. Mainboard
Pongify/Rapid Hybridization – Unconditional removal is a pretty good thing to have, and while this card leaves behind a 3/3 token, that's often something Merfolk can beat (especially with something like Harbinger or Tidebinder). It requires a bit of effort to use effectively, but it might be useful. Mainboard
Repeal – This card is somewhat mana-intensive, but a tempo play that can hit any nonland permanent with card draw attached is the sort of powerful catchall effect Merfolk is always in the market for. It will require a specific kind of Merfolk 75 and opposing metagame to be successful, but if you find yourself in those circumstances, it can be a very strong choice. Mainboard
Spell Snare – While this card is narrow, many decks in Modern rely on 2-drops, and some do so quite heavily. Having a piece of interaction that's live on the draw and easy to keep mana open for has some potential, and it can always be sided out if it's poor against a given opponent. This card has not been used by many Merfolk players, but perhaps it should be kept in mind as an option. Mainboard
Swan Song – The drawback might scare some people away, but it’s a decent cheap counterspell to bring in from the sideboard against the likes of combo decks. A 2/2 flier can’t outrace a Merfolk deck on its own, and shutting down their combo will give you the opportunity to race. Sideboard
Thassa's Rebuff – While a bit on the win-more end (this only becomes a potent counterspell once you've established a board state), this can potentially serve an important purpose in Merfolk, which is as a catch-all to ensure your opponent does not mount a comeback once you are ahead. I can see the upsides and downsides to it, but it's hard to tell which outweighs the other without more testing. Sideboard
Unsubstantiate – A very flexible spell, this card is basically half a Remand stapled to an Unsummon, with the bonus of that it can hit uncounterable spells such as Abrupt Decay, Volcanic Fallout, and Supreme Verdict. However, the fact that it is purely a tempo play makes its applicability questionable. It has some potential. Mainboard
Wizard's Retort – While this card's discount effect (which is the major thing that makes it a playable consideration) keys off Wizards as opposed to Merfolk, many of the Merfolk that see play in Modern happen to be Wizards. If you don't feel like you have enough catchall counterspells for your liking, this may be something to consider. Sideboard
Lands
Gemstone Caverns – This land is an interesting option for "stealing" the play and making sure you can keep up on board development. While losing a card is a harsh cost, it can be very useful in openers where you don't have an Aether Vial, or are looking to slam something like a Chalice of the Void as soon as possible. Might be worth a test. Mainboard
Lonely Sandbar – While being a tapland is an undeniable drawback, the fact that you can cash these in for a card if you have excess lands make them pretty handy. It's unclear whether a redraw is better for us than the creature-land effect of something like Faerie Conclave, but it's probably worth experimenting with. Mainboard
Planeswalkers
Ashiok, Dream Render – This card doubles as search hate and graveyard hate, which makes it useful in a variety of matchups. While 3 mana for a noncreature spell is a bit on the high end of what we'd like to pay, effects this definitive may be worth it if you expect to face the decks that seem most susceptible to its static effect (Primeval Titan decks, Whir of Invention decks, and possibly graveyard decks, if used as a supplement to more conventional graveyard hate).
This section is dedicated to finding somewhat cheaper alternatives to some popular cards, as the likes of Aether Vial, Cavern of Souls, and Mutavault can be pretty expensive from the real-world point of view.
Ghost Quarter – If you can't afford Mutavaults, this is a handy little disruptive land that can punish big-mana decks and eat up manlands, and it can also target one of your lands if you happen to be starved for U. You can do worse. Mainboard
Merfolk Sovereign – In the event that you're finding some of the Lords a bit hard to come by, this can offer you a bit of extra pump and an unblockability effect in case you're having trouble evading blockers. Mainboard
1. Use Aether Vial for early pressure. A T1 Vial can help you put a lot of boots on the ground quickly, and that can overwhelm an opponent that's not equipped to deal with multiple creatures hitting the table in rapid succession. This will get you a lot of free wins.
2. Aether Vial helps your creatures dodge counterspells and removal. Remember that the Vial's effect can be used any time you could play an instant – this means you can flash creatures in as a combat trick (for example, using a Harbinger of the Tides to erase an attack or a Lord to mess up your opponent's combat math). You can also bring your creatures in on your opponent's end step in order to dodge sorcery-speed removal (this is especially important against sweepers like Supreme Verdict).
Another note is that because the creatures are being put into play via the Vial's activated ability, they are not being cast. That means that opposing counterspells do not work. On the bad side, it also means they won't trigger the likes of Merrow Reejerey.
3. Aether Vial's charge counter effect is optional. That means you don't have to tick it up if you don't want to. This is especially relevant in Merfolk, because the deck is crawling with useful 2-drops that you'll want to get on the battlefield as quickly as possible. As such, I would recommend you think long and hard before you tick up your Vial from 2 charge counters.
4. Aether Vial can help you be aggressive and interactive at the same time. While I did mention that being aggressive with Vial can get you free wins, there are decks that strategy doesn't work against, namely fast combo decks. In that case, you can use your Vial to keep steady pressure on your opponent while you hold up some form of disruption (usually bounce or counterspell effects) to stuff whatever they're up to.
One of the major decisions a Merfolk player has to make when creating his or her deck is to decide whether to splash for a second color. Most Modern decks are multiple colors, in large part because the versatility provided by the larger toolbox is necessary in order for the deck to function competitively.
This has NOT the case for Merfolk historically – the mono-U build has been the most competitive variant for a long time, and the reason why was the excellent consistency in the mana base thanks to only needing U mana for spells, and (to a lesser extent) the lack of self-inflicted damage by opting to stay away from fetchlands and shocklands. Because of this, the answer to the question posited at the start of the section in the past was NOT TO SPLASH. For more on that, check out Nikachu_'s informative video on why the W splash wasn't worth it in the past.
However, recent additions to the card pool have changed this paradigm. One potential splash that seems to be a strong option is UG Merfolk (aka Tropical Fish, hat tip to Reddit). The reason why this variant stands above the rest is because it features a significant amount of quality creatures with the Merfolk type, thanks to Ixalan and Rivals of Ixalan. If you are dead-set on splashing a color in your Merfolk deck, I strongly recommend that it be G in order to take advantage of this creature selection. Here are some of the options available to a pilot that does so:
UG Merfolk/Tropical Fish:
Botanical Sanctum – You need access to G without compromising your U source count, and this is the best option available that doesn't cost you life. Essential to making this splash work. Mainboard
Breeding Pool – About as good a source of U and G as you’re going to find in Modern. Mainboard
Collected Company – While this card is undeniably powerful, I'm of the opinion it's a bit of an awkward fit in Merfolk, due to its high cost and Merfolk's lack of conventional mana acceleration. However, if you're looking for card advantage in UG colors, it's hard to do better. Mainboard
Heroic Intervention – While this is a somewhat clunky card, it is a way to protect your entire team from sweepers such as Supreme Verdict, which is something few cards in the Merfolk toolbox are capable of doing. Worth considering. Sideboard
Kumena, Tyrant of Orazca – While this card runs somewhat at odds with Merfolk's aggressive gameplan, its effects combined with its resilient body make it an interesting option if you expect games to go long. Mainboard or Sideboard
Kumena's Speaker – If you want to streamline your deck and make it more aggressive, this is a quality 1-drop with the right creature type. Mainboard
Jungleborn Pioneer – 2 bodies for 3 mana is a pretty solid rate, and the fact that one of them has hexproof is also pretty interesting. Worth considering. Mainboard
Merfolk Branchwalker – While this card is definitely no Silvergill Adept, a 2-drop that can get you a bit of value upon entering the battlefield is far from a bad thing. A card to consider in certain shells. Mainboard
Merfolk Mistbinder – Another 2-mana Lord effect is a major incentive for splashing G, and it allows you to lower the deck's curve in a significant manner. I consider this an essential component of the Tropical Fish variant. Mainboard
Flooded Strand/Misty Rainforest/Polluted Delta/Scalding Tarn – Because Merfolk is a U-based deck, and I do not recommend that you play any basic land other than Islands, it does not matter which fetchland you use - all of them can find your shocks, and thus all of them are helpful at making sure your mana is as clean as it can be. Mainboard
Natural State – A cheap and convenient way to remove most troublesome artifacts and enchantments that Merfolk would care about. Zaps everything from Cranial Plating to Ensnaring Bridge to Ghostly Prison, and as such has value. Sideboard
Reclamation Sage – Kills any artifact or enchantment, and is a creature (which makes it Vial-friendly). What's not to like? Sideboard
Shapers' Sanctuary – This card is a nice way to ensure your gameplan won't get run out of gas by copious amounts of spot removal. One of the nicer tools made available by the G splash. Sideboard
For completeness' sake, I am also including some card options in other colors below:
WU Merfolk:
Blessed Alliance – This can be a powerful tool against decks that like to come in with pump spells and large attackers (Bogles, Death's Shadow, Eldrazi, Infect, UR Prowess), and of course is handy against Burn. A pretty good card to have. Sideboard
Disenchant – Not a fancy effect, but a useful one. U doesn’t really have many ways to blow up permanents once they hit play, and this card fixes that problem. Strictly a sideboard card, though. Sideboard
Hallowed Fountain – It’s not as smooth as some of the other W sources we have access to, but it’s fetchable and thus does the job. Mainboard
Harm's Way – This is a sneaky little trick to unleash on your opponent. Shifting damage around is a great way to turn a combat situation on its head, and it oftentimes turns a Lightning Bolt played as a removal spell into a removal spell for you. A bit tricky because you have to hold up W until the right moment, but the payout is well worth it. Could be run in either the main or side. Mainboard or Sideboard
Kataki, War's Wage – A potent way to severely damage Affinity decks while not really damaging your own hopes. His only weakness is his 2/1 body, which is quite easy to remove. Quality sideboard material. Sideboard
Militia Bugler – While not a Merfolk in its own right, its value effect synergizes very well with a deck that has lots of small creatures it makes dangerous with pump effects. A bit experimental, but if you're looking to grind, you'll be hard-pressed to find a better effect on a creature in this format. Mainboard
Rest in Peace – Arguably the most potent piece of graveyard hate available to you, it being on the field can basically win you the game against a deck that’s dependent on the ‘yard. It's narrow enough that it should come in off the sideboard, though. Sideboard
Seachrome Coast – Painless source of W that doesn’t compromise your U source count? Sign me up! Mainboard
Stony Silence – This usually stops Affinity cold when it hits the board, but it should be noted that it doesn’t play nice with our Aether Vial. Still, anything that houses our worst matchup is worth including in your sideboard, and it does double duty against Tron. Sideboard
Sygg, River Guide – A bit on the slow side, but on-demand protection for your creatures is a juicy carrot. However, the mana-intensiveness of the effect means that you probably won’t get to use it until the later game. Still, it's a reasonable on-tribe body with a powerful effect, and that is worth considering. Mainboard
Worship – This card is a haymaker against creature-based aggro decks with limited ability to interact with non-creature permanents, and can sometimes just win you games outright. It’s on the expensive side, though, so casting it can sometimes be a bit of a challenge. I would consider this a sideboard card, but a good one. Sideboard
UB Merfolk:
Collective Brutality – While Merfolk isn't exactly the kind of deck that likes pitching cards from its own hand (unless they're extra Aether Vials), this effect can be quite handy at shutting down fast decks that rely on a combination of creatures and spells to kill you quickly (Burn, Devoted Company, Elves, and Infect being the major examples). Worth considering. Sideboard
Darkslick Shores – If you’re going to splash B, a painless source of it is invaluable. Mainboard
Fatal Push – Quality removal for most creatures you care about. One of the main reasons to consider the splash. Mainboard
Inquisition of Kozilek – Early game disruption can make for a potent T1 play, and it has tons of relevant targets in Modern. Its only flaw is that it requires us to splash. It probably takes the place of some of the counterspells that other Merfolk 75s would play. Mainboard or Sideboard
Thoughtseize – One of the greatest T1 plays you could have, its only flaw is that it requires B. The life loss can also sting when you’re already damaging yourself to be able to cast it in the first place. It mostly serves as a counterspell-substitute. Mainboard or Sideboard
Watery Grave – Probably your most reliable source of B while not neglecting U. Plays nice with fetches, so you’ll need it. Mainboard
UR Merfolk:
Blood Moon – This card synergizes with Merfolk's innate land hate plan in order to lock most opponents out of the game. Can be a potent maindeck hate piece in certain metagames, but overall it's likely at its best coming in off the board as a shutdown piece for decks soft to it. Mainboard or Sideboard
Electrickery – A potent sideboard bullet against weenie-based decks, this can blow up board states that have gone too wide for you to deal with otherwise, and it'll do so for cheap. Useful card to have in your toolbox. Sideboard
Izzet Charm – This is basically the Deluxe Edition of Spell Pierce. It costs more mana, but it adds 2 potential modes, so it's never a dead card in hand. Worth considering. Mainboard or Sideboard
Izzet Staticaster – This card offers repeatable elimination of swarms of creatures, provided they have the same name. As that heavily implies, it's at its best when handling tokens, which is something that Merfolk can have trouble with on the occasions we can't just islandwalk past them. It's a nice backup plan if you expect to see lots of tokens. Sideboard
Lightning Bolt – The workhorse burn spell of Modern. We've felt its wrath many a time, so we know how good it can be to clear blockers, remove attackers, disrupt combos, or just finish off wounded opponents. You won't need much more bounce or removal if you're packing this. Mainboard
Steam Vents – This is about as good a source of R as you'll find. Pack it and figure the rest out later. Mainboard
Spirebluff Canal – While fastlands can be inconvenient if they're your 4th land drop, a painless source of U and R is critical in order to pull this splash off. Mainboard
Wizard's Lightning – This card's effect keys off a different tribe than Merfolk, but it's a tribe Merfolk has a lot of overlap with. If you find yourself wanting more than 4 Bolt effects when running this splash, this may be a worthy consideration. Mainboard
Many thanks to Brentane for the sweet banner.
Merfolk (also known as Fish) is a U-based tempo deck with a strong aggro secondary element that is built around tribal synergies. Merfolk is a mostly fair deck, with most iterations striking a balance between being linear and proactive, and being interactive and reactive. It employs lots of cheap, efficient creatures along with Aether Vial and some catchall disruption in order to overwhelm its opponents. For a more thorough (though somewhat outdated) overview of the Merfolk deck, check out Merfolk Joe's Guide to Modern Merfolk video series.
Here are some reasons why you might consider Merfolk as the deck for you:
Here are a few links you can check out if you want more Merfolk content.
Nikachu's YouTube Channel – Nikachu is a very seasoned Merfolk player that has a deep repository of videos you can peruse to get up to speed on how to play Merfolk.
Merfolk Joe's YouTube Channel – Merfolk_Joe is another seasoned Merfolk player, and he has some very polished and informative videos of Merfolk in Modern.
LordMajicus' YouTube Channel – LordMajicus is a veteran Merfolk pilot that runs both stock and innovative lists on Magic Online.
The seer's YouTube Channel – Here is another channel with one of our fellow Merfolk players testing the deck against the field.
MagicMaxe's YouTube Channel – This channel has videos of paper matches for Merfolk for both Modern and Legacy.
FishMTG Subreddit – An entire subreddit community focusing on Merfolk decks. Some alternative discussion to be found here.
Petr Sochurek's Merfolk primer – Petr is widely regarded as one of most influential voices in constructing Modern Merfolk as we know it, and he has recently released a 3-part primer series discussing the deck in great detail.
Nicholas Bradley's Summary of Merfolk in the Meta – This is a seasoned Merfolk player's take on the deck and its matchups.
FishMTG Discord – If you want to discuss Merfolk in real time, this is a Discord server dedicated to our deck across formats.
Note: Please post your decklist (including sideboard) when asking for advice on this thread. Help us help you.
02/11/2016 - Added Sea's Claim to the "land hate" category in the Matchups and Sideboarding section where appropriate.
02/15/2016 - Updated the Matchups and Sideboarding section where appropriate.
02/17/2016 - Updated the description for Chalice of the Void in the Preferred Card Choices section. Updated Sample Decklists section.
02/22/2016 - Added Grafdigger's Cage to the Preferred Card Choices section and the Matchups and Sideboarding section where appropriate. Added MagicMaxe's YouTube channel to the Links section.
02/25/2016 - Updated the Matchups and Sideboarding section where appropriate.
02/29/2016 - Added Pithing Needle to the Matchups and Sideboarding section where appropriate.
03/03/2016 - Updated the Matchups and Sideboarding section where appropriate.
03/16/2016 - Updated the Modern Merfolk Core Decklist and the Matchups and Sideboarding sections where appropriate. Added Dario Casati's list to the Sample Decklists section.
03/27/2016 - Added Essence Flux, Invasive Surgery, and Threads of Disloyalty to the Preferred Card Choices section and the Matchups and Sideboarding section where appropriate.
04/05/2016 - Added Stonybrook Banneret to the Budget Options section.
04/11/2016 - Added Budget deck to the Sample Decklists section.
04/23/2016 - Updated the Sample Decklists section where appropriate. Added Sea Gate Wreckage to the Preferred Card Choices section and the Matchups and Sideboarding section where appropriate.
04/26/2016 - Added MerfolkJoe's YouTube channel to the Links section.
04/29/2016 - Updated the Matchups and Sideboarding section where appropriate.
05/04/2016 - Updated the Matchups and Sideboarding section where appropriate.
05/10/2016 - Updated the Sample Decklists section where appropriate.
05/18/2016 - Updated the Sample Decklists section where appropriate.
05/22/2016 - Added Simon ****sky's and Przemek Knocinski's Merfolk lists to the Sample Decklists section.
05/23/2016 - Edited the Links and Sample Decklists sections as appropriate.
06/08/2016 - Updated the Matchups and Sideboarding section where appropriate.
06/27/2016 - Updated the Sample Decklists section where appropriate.
06/29/2016 - Edited description for Remand in the Preferred Card Choices section.
07/08/2016 - Updated the Sample Decklists section where appropriate.
07/20/2016 - Updated the Preferred Card Choice section where appropriate.
07/26/2016 - Added Merfolk Joe's Guide to Modern Merfolk and Petr Sochurek's Merfolk primer to the Introduction and Links sections, respectively.
07/27/2016 - Updated the Matchups and Sideboarding section where appropriate.
07/28/2016 - Added the Experimental Card Choices section and updated the Modern Merfolk Core Decklist and Sample Decklists sections.
08/01/2016 - Updated the Sample Decklists section where appropriate.
08/14/2016 - Updated the Sample Decklists section where appropriate.
08/17/2016 - Edited Introduction and Why Merfolk? sections where appropriate.
09/08/2016 - Updated the Matchups and Sideboarding section where appropriate.
09/21/2016 - Edited the spelling of Aether Vial to accomodate the new printing.
09/27/2016 - Added Flashfreeze to the Experimental Card Choices section.
10/13/2016 - Updated Introduction section and Merfolk Joe's Merfolk list in the Sample Decklists section.
10/14/2016 - Updated the Matchups and Sideboarding section where appropriate.
10/30/2016 - Updated the To Splash, or Not to Splash? and Sample Decklists sections where appropriate.
11/09/2016 - Updated the Matchups and Sideboarding section where appropriate.
11/17/2016 - Added Skred Red to the Matchups and Sideboarding section.
11/22/2016 - Updated the Matchups and Sideboarding section where appropriate, and edited formatting.
11/23/2016 - Updated the GX Tron and Temur Midrange entries in the Matchups and Sideboarding section.
12/03/2016 - Updated rothgar13's Merfolk list in the Sample Decklists section.
12/05/2016 - Added Blossoming Defense and Fog to the To Splash, or not to Splash? section.
12/23/2016 - Updated the Matchups and Sideboarding and Sample Decklists sections.
12/28/2016 - Updated the primer in general.
01/17/2017 - Updated the Matchups and Sideboarding and Sample Decklists sections.
01/25/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section.
01/30/2017 - Added Smuggler's Copter to the Experimental Card Choices section.
02/06/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section.
02/07/2017 - Updated rothgar13's Budget Merfolk list in the Sample Decklists section.
02/14/2017 - Updated the Matchups and Sideboarding section.
02/21/2017 - Added Vendilion Clique to the Preferred Card Choices section.
03/01/2017 - Added ModernNexus' Merfolk primer to the Links section.
03/15/2017 - Updated the Matchups and Sideboarding section where appropriate.
03/19/2017 - Added Ceremonious Rejection to the Experimental Card Choices section and Vendilion Clique to the Matchups and Sideboarding section.
03/28/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section.
03/31/2017 - Edited the Ad Nauseam entry in the Matchups and Sideboarding section.
04/01/2017 - Updated rothgar13's Merfolk list in the Sample Decklists section.
04/17/2017 - Updated the Matchups and Sideboarding section and rothgar13's Merfolk list in the Sample Decklists section.
05/02/2017 - Updated the Matchups and Sideboarding section.
05/26/2017 - Added the Merfolk List and Sideboarding Guide (by yours truly) to the Links section and updated rothgar13's Merfolk list in the Sample Decklists section. Also updated the Matchups and Sideboarding section.
06/06/2017 - Updated the Sample Decklists section.
06/26/2017 - Updated the Matchups and Sideboarding and Sample Decklists sections.
07/05/2017 - Updated the Matchups and Sideboarding section.
07/29/2017 - Added Nicholas Bradley's Merfolk article to the Links section.
08/04/2017 - Updated the Matchups and Sideboarding section. Added Gemstone Caverns, Pongify/Rapid Hybridization, and Tideshaper Mystic to the Experimental Card Choices section.
08/11/2017 - Updated the Sample Decklists section.
10/12/2017 - Added Kopala, Warden of Waves to the Preferred Card Choices section. Added Sorcerous Spyglass to the Experimental Card Choices section. Updated the Sample Decklists section.
10/18/2017 - Updated the Preferred Card Choices, Experimental Card Choices, and To Splash, or Not to Splash? sections.
11/04/2017 - Added Watertrap Weaver to the Experimental Card Choices section.
12/08/2017 - Updated the Sample Decklists section.
01/10/2018 - Updated the primer in general.
04/25/2018 - Added Damping Sphere and Merfolk Trickster to the Preferred Card Choices section. Updated the Sample Decklists section.
04/30/2018 - Added Deprive to the Recommended Card Choices section.
05/16/2018 - Updated the Sample Decklists section. Added Coralhelm Commander to the Recommended Card Choices section.
07/23/2018 - Updated the Sample Decklists section. Added MHayashi's Merfolk to the Sample Decklists section. Added Repeal to the Experimental Card Choices section.
08/02/2018 - Updated the To Splash, or not to Splash? section.
08/06/2018 - Added the FishMTG Discord link to the Links section.
08/11/2018 - Edited the primer in general.
08/18/2018 - Removed the damaged ModernNexus Merfolk Primer link from the Links section.
09/26/2018 - Addded Venser, Shaper Savant to the Preferred Card Choices section.
10/22/2018 - Updated Nikachu's Merfolk in the Sample Decklists section. Moved Mistcaller from the Experimental Card Choices section to the Preferred Card Choices section. Added Peek to the Experimental Card Choices section.
03/01/2019 - Updated the primer in general. Began overhaul of Matchups and Sideboarding section.
03/25/2019 - Finished the Established Decks sub-section of the Matchups and Sideboarding section. Added Cryptic Command to the Experimental Card Choices section.
03/26/2019 - Updated the Introduction and Why Merfolk? sections.
03/28/2019 - Finished the Fringe Decks sub-section of the Matchups and Sideboarding section.
04/05/2019 - Updated the Preferred Card Choices and Experimental Card Choices sections.
05/07/2019 - Added Thassa, God of the Sea to the Preferred Card Choices section. Updated the Matchups and Sideboarding section. Added LordMajicus' YouTube channel to the Links section.
05/08/2019 - Added Ashiok, Dream Render to the Experimental Card Choices section.
07/15/2019 - Added Force of Negation to the Modern Merfolk Core Decklist section. Added Waterlogged Grove to the Preferred Card Choices section. Added Lonely Sandbar and Phyrexian Revoker to the Experimental Card Choices section. Updated the Matchups and Sideboarding section.
Dismember
Harbinger of the Tides
Spell Pierce
Spreading Seas
Vapor Snag
Echoing Truth (sideboard)
Hurkyl's Recall (sideboard)
Negate (sideboard)
Relic of Progenitus (sideboard)
Tidebinder Mage (sideboard)
Unified Will (sideboard)
The good news is that none of those cards is above $3 USD a pop (and many are much less than that), so once you get the Vials, Vaults, and Catchers, the financial hard part's over. True-Name Nemesis is a great card, but sadly it's not Modern-legal, so you won't need any more for this edition of the deck.
Doesn't actually work. Echoing Truth targets the Image, the Image is sacrificed, and the spell fizzles because it has no legal targets. It's the same reason Path to Exile won't get you a free land when it targets an Image. If that's one of the Image's major selling points, I think it's time you look elsewhere.
Play through Æther Vial, and don't over-extend. Commit enough resources for a quick clock, but don't blow your whole hand on it.