Presuming you declared no additional targets for Fireball, the total cost to cast Fireball with X = 3 would be 2R. Determining the total cost of a spell is usually...
(1) Start with the mana cost (or alternative cost, such as flashback or overload). Since there's an X in the cost, you choose X in an earlier step of casting the spell.
(2) Add any additional costs, such as the 1 for additional targets.
(3) Subtract any cost reductions, such as 1 due to Goblin Electromancer's ability.
...which gives you 3R as the mana cost, when X = 3, and you subtract 1 from this to determine the total cost. That means 2R. (The total cost to cast a spell could also be directly modified, such as by Trinisphere, but that modification occurs after you follow these three general steps.)
Edit: And since you stealth edited in Banefire after I wrote my answer to address the originally mentioned Fireball, it would be 4R for Banefire.
Presuming you declared no additional targets for Fireball, the total cost to cast Fireball with X = 3 would be 2R. Determining the total cost of a spell is usually...
(1) Start with the mana cost (or alternative cost, such as flashback or overload). Since there's an X in the cost, you choose X in an earlier step of casting the spell.
(2) Add any additional costs, such as the 1 for additional targets.
(3) Subtract any cost reductions, such as 1 due to Goblin Electromancer's ability.
...which gives you 3R as the mana cost, when X = 3, and you subtract 1 from this to determine the total cost. That means 2R. (The total cost to cast a spell could also be directly modified, such as by Trinisphere, but that modification occurs after you follow these three general steps.)
Edit: And since you stealth edited in Banefire after I wrote my answer to address the originally mentioned Fireball, it would be 4R for Banefire.
Thanks for the help. And I'm sorry I wasn't fast enough with the edit. I figured Banefire would make for a simpler explanation.
Private Mod Note
():
Rollback Post to RevisionRollBack
Vive, vale. Siquid novisti rectius istis,
candidus inperti; si nil, his utere mecum.
~~~~~
If I cast EE with X = 3 and happen to reveal a sorcery/instant that equals 4, do I get to cast the 4cc spell for free?
Private Mod Note
():
Rollback Post to RevisionRollBack
"When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that justifies it." Frederic Bastiat
To add to the above answer: Goblin Electromancer and other effects that change the amount of mana you would need to cast something do not affect converted mana costs. So while you would normally be able to cast, say, Foresee for three mana if you have an Electromancer, this does not make Foresee eligible to be cast off of an Epic Experiment that is letting you cast any revealed instant/sorcery with CMC 3 or less.
Without the goblin out, you can't make x=4 if you have only 4 mana total, but why do people make x=4 when it is out? I never quite got X spells with mana reduced costs.
To me, getting a 'free' extra damage when people put out x spells with the goblin or other cost reduction things is like casting Altar's Reap for free if you have no creatures in play.
Without the goblin out, you can't make x=4 if you have only 4 mana total, but why do people make x=4 when it is out? I never quite got X spells with mana reduced costs.
To me, getting a 'free' extra damage when people put out x spells with the goblin or other cost reduction things is like casting Altar's Reap for free if you have no creatures in play.
You can choose a value for X that is one higher than you would otherwise be able to pay for because of how the steps of casting spells play out. Without cost reduction effects, it can look like the game defines X based on how much mana you sink into it, but that isn't how it actually works.
When you cast a spell with X in its cost, you choose a value for X first. Then you determine how much mana the spell costs (Fireball for X=4 costs 4R, non-miracled Bonfire of the Damned for X=4 costs 8R, and so on.) Then you apply any effects that increase or decrease costs, so at this point the Goblin Electromancer steps in and says that you only need to spend 3R on that 4-point Fireball.
The Altar's Reap situation is different from the above only in terms of what effects exist that can interact with it. Determining that you need to sacrifice a creature is done along with determining the total cost to cast the spell. It's just that there aren't any cards (that I know of) that have an effect that allows you to cast spells without paying additional costs.
Private Mod Note
():
Rollback Post to RevisionRollBack
To post a comment, please login or register a new account.
Let's say I want to cast a Banefire to deal 5 damage. Would I pay 5R or 4R if I control Goblin Electromancer?
candidus inperti; si nil, his utere mecum.
~~~~~
Presuming you declared no additional targets for Fireball, the total cost to cast Fireball with X = 3 would be 2R. Determining the total cost of a spell is usually...
(1) Start with the mana cost (or alternative cost, such as flashback or overload). Since there's an X in the cost, you choose X in an earlier step of casting the spell.
(2) Add any additional costs, such as the 1 for additional targets.
(3) Subtract any cost reductions, such as 1 due to Goblin Electromancer's ability.
...which gives you 3R as the mana cost, when X = 3, and you subtract 1 from this to determine the total cost. That means 2R. (The total cost to cast a spell could also be directly modified, such as by Trinisphere, but that modification occurs after you follow these three general steps.)
Edit: And since you stealth edited in Banefire after I wrote my answer to address the originally mentioned Fireball, it would be 4R for Banefire.
Thanks for the help. And I'm sorry I wasn't fast enough with the edit. I figured Banefire would make for a simpler explanation.
candidus inperti; si nil, his utere mecum.
~~~~~
If I cast EE with X = 3 and happen to reveal a sorcery/instant that equals 4, do I get to cast the 4cc spell for free?
To me, getting a 'free' extra damage when people put out x spells with the goblin or other cost reduction things is like casting Altar's Reap for free if you have no creatures in play.
When you cast a spell with X in its cost, you choose a value for X first. Then you determine how much mana the spell costs (Fireball for X=4 costs 4R, non-miracled Bonfire of the Damned for X=4 costs 8R, and so on.) Then you apply any effects that increase or decrease costs, so at this point the Goblin Electromancer steps in and says that you only need to spend 3R on that 4-point Fireball.
The Altar's Reap situation is different from the above only in terms of what effects exist that can interact with it. Determining that you need to sacrifice a creature is done along with determining the total cost to cast the spell. It's just that there aren't any cards (that I know of) that have an effect that allows you to cast spells without paying additional costs.