7/6 vs 6/4, same cost. My question is, why would the creators do this? Doesn't this make Craw Worm completely useless? Why would anyone have it in a deck? There are many other examples. Shock vs Lightning Bolt, etc. Is this just so that people will keep buying more cards, since newer cards are stronger than older cards? Won't this eventually lead to 20/20 cards that cost 2 mana?
Kind of new to the game. Just trying to understand the logic here.
You're looking at 2 cards that were in the original release of the game - Craw Wurm and Lightning Bolt. When the game was first released, there were only about 300 cards. Wizards had no clue what the game would eventually become, nor did they fully grasp how much balance there really needed to be within the game.
Craw Wurm was one of the biggest creatures when the game was first released in 1993. Primordial Wurm was released 25 years later in Dominaria. The game changed a lot over that time. Craw Wurm seemed weak compared to other creatures with the same or similar casting costs, so they updated it.
Lightning Bolt actually went in the other direction, they felt it was too powerful for it's casting cost, so made a weaker version of it with Shock. This happened only 4-5 years after the original release of the game.
One reason to have the weaker card in a deck is because the weaker card is legal in the format you're playing and the stronger one isn't. For example, Shock is currently legal in Standard format (most recently printed in a Standard-legal set in M20, released July 2019), while Lightning Bolt isn't (most recently printed in a Standard-legal set in M11, released July 2010).
Or maybe you're playing in a Limited event, and the worse card of the two is in the set you're playing with while the better one isn't.
Another reason to have the weaker card in a deck is because you already have 4 copies (or 1 copy in a singleton format like EDH/Commander) of the stronger card, and want more. If you have 4 Lightning Bolts in your deck, you aren't allowed to have a 5th. But you could add 4 Shocks, which, while not as good as Lightning Bolt, may be more useful to what your deck is trying to do than any other alternative.
Sometimes, it is the case that a strictly-better card is printed, and you don't want 5-8 copies of the effect in a deck, so the worse card stops seeing play. That's okay. The game is nearly 27 years old, and there have always been cards that don't see competitive play, even without strictly better versions available. Time marches ever onwards, and things change. Without change, the game would become boring.
Wizards does attempt to keep things in balance, but that doesn't mean keeping everything the same.
If you track the lineage of Craw Wurm to Primordial Wurm you can see that the 6 CMC green vanilla creatures has had a tiny amount of power creep over the years. To wit, over the course of 27 years we've seen the following cards:
I'm not counting Tuinvale Treefolk even though it is technically a Vanilla creature, but having an Adventure tacked on puts the creature, IMHO, into a different class.
If you examine the cards carefully, you'll notice that the designers kind of bat around the power/toughness peaking at Vorstclaw in 2012. Take note of the actual mana cost on some of the cards too. Craw and Barbtooth are both identical in power and toughness and even how much mana is spent, but the fact that Barbtooth requires only one G and Craw requires GG makes Barbtooth the better of the two. You can get away with having only one Forest in play and any other colors as long as you have at least five plus G to cast Barbtooth Wurm. There's more to it than that as Lithl explained. I'm just over simplifying to illustrate a point.
So yeah... it is what it is. And for the most part, WotC has done a reasonably good job in not letting the power levels of the cards get too out of hand too quickly too often. Not perfect over the course of 27 years but compared to a certain other card game, it's kept in check.
The different sizes are more to shake up drafts and limited games in general, as thats the place a common is actually played.
Nobody in constructed plays the bad cards anyway, and even then you will have the "best" option and anything else doesnt matter.
At some point the game had somewhat of a power scaling curve in mind, so each manacost had an idea to balance power/thoughness around and especially make vanilla creatures feel appropriate for each color.
That is no longer the case (at least a lot less so).
----
In the past they pushed p/t on hard manacosts, so if a card was better it also had more color commitment.
But currently you hardly ever find a card that has 3+ colored manasymbols anymore, unless they push it like a gimmick (like for the Devotion mechanic).
With obscene cards like The Scarab God that has almost no color commitment, it dwarfs almost anything else.
It could cost 8UB and still be crazy a massive bomb in Limited formats ...
Stuff like this pretty much "ignores" any balancing approach and banks that the format fixes the issue itself, by speed and the powerlevel of answers (as 1 mana removal against creatures keep pretty much any creature in check no matter how crazy they make them).
Since you say you're somewhat new, something that hasn't been mentioned yet is that rarity also plays into the cost/benefit of similar cards. You can find various instances where two cards do the same thing, but the casting cost is different and reflected in the rarity (how often you pull the card in a pack/box). While the cards so far discussed above have all been commons, more variation in similar concepts comes through with cards of other rarity, such as say the Gigantosausur, still being "vanilla" but cheaper and much bigger, and also rare. But note that as TheOnlyOne652089 mentioned, it's color cost is also harder to reach with five green.
7/6 vs 6/4, same cost. My question is, why would the creators do this? Doesn't this make Craw Worm completely useless? Why would anyone have it in a deck? There are many other examples. Shock vs Lightning Bolt, etc. Is this just so that people will keep buying more cards, since newer cards are stronger than older cards? Won't this eventually lead to 20/20 cards that cost 2 mana?
Kind of new to the game. Just trying to understand the logic here.
Craw Wurm was one of the biggest creatures when the game was first released in 1993. Primordial Wurm was released 25 years later in Dominaria. The game changed a lot over that time. Craw Wurm seemed weak compared to other creatures with the same or similar casting costs, so they updated it.
Lightning Bolt actually went in the other direction, they felt it was too powerful for it's casting cost, so made a weaker version of it with Shock. This happened only 4-5 years after the original release of the game.
One reason to have the weaker card in a deck is because the weaker card is legal in the format you're playing and the stronger one isn't. For example, Shock is currently legal in Standard format (most recently printed in a Standard-legal set in M20, released July 2019), while Lightning Bolt isn't (most recently printed in a Standard-legal set in M11, released July 2010).
Or maybe you're playing in a Limited event, and the worse card of the two is in the set you're playing with while the better one isn't.
Another reason to have the weaker card in a deck is because you already have 4 copies (or 1 copy in a singleton format like EDH/Commander) of the stronger card, and want more. If you have 4 Lightning Bolts in your deck, you aren't allowed to have a 5th. But you could add 4 Shocks, which, while not as good as Lightning Bolt, may be more useful to what your deck is trying to do than any other alternative.
Sometimes, it is the case that a strictly-better card is printed, and you don't want 5-8 copies of the effect in a deck, so the worse card stops seeing play. That's okay. The game is nearly 27 years old, and there have always been cards that don't see competitive play, even without strictly better versions available. Time marches ever onwards, and things change. Without change, the game would become boring.
Wizards does attempt to keep things in balance, but that doesn't mean keeping everything the same.
Two Score, Minus Two or: A Stargate Tail
(Image by totallynotabrony)
Craw Wurm printed in 1993
Barbtooth Wurm 1998
Vastwood Gorger, 2009
Alpha Tyrranax, 2010
Kindercatch, 2011
Vorstclaw. 2012
Tusked Colossodon, 2014
Canopy Gorger, 2016
Cowl Prowler, 2016
Primordial Wurm, 2018
Nyxborn Colossus, 2020
I'm not counting Tuinvale Treefolk even though it is technically a Vanilla creature, but having an Adventure tacked on puts the creature, IMHO, into a different class.
If you examine the cards carefully, you'll notice that the designers kind of bat around the power/toughness peaking at Vorstclaw in 2012. Take note of the actual mana cost on some of the cards too. Craw and Barbtooth are both identical in power and toughness and even how much mana is spent, but the fact that Barbtooth requires only one G and Craw requires GG makes Barbtooth the better of the two. You can get away with having only one Forest in play and any other colors as long as you have at least five plus G to cast Barbtooth Wurm. There's more to it than that as Lithl explained. I'm just over simplifying to illustrate a point.
So yeah... it is what it is. And for the most part, WotC has done a reasonably good job in not letting the power levels of the cards get too out of hand too quickly too often. Not perfect over the course of 27 years but compared to a certain other card game, it's kept in check.
The different sizes are more to shake up drafts and limited games in general, as thats the place a common is actually played.
Nobody in constructed plays the bad cards anyway, and even then you will have the "best" option and anything else doesnt matter.
At some point the game had somewhat of a power scaling curve in mind, so each manacost had an idea to balance power/thoughness around and especially make vanilla creatures feel appropriate for each color.
That is no longer the case (at least a lot less so).
----
In the past they pushed p/t on hard manacosts, so if a card was better it also had more color commitment.
But currently you hardly ever find a card that has 3+ colored manasymbols anymore, unless they push it like a gimmick (like for the Devotion mechanic).
With obscene cards like The Scarab God that has almost no color commitment, it dwarfs almost anything else.
It could cost 8UB and still be crazy a massive bomb in Limited formats ...
Stuff like this pretty much "ignores" any balancing approach and banks that the format fixes the issue itself, by speed and the powerlevel of answers (as 1 mana removal against creatures keep pretty much any creature in check no matter how crazy they make them).
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