Highest possible power of a creature

What is the highest possible power of a creature, assuming a deck of 60 cards and infinite time?

• Generally, there's no shortage of combos that'll let you go infinite, so the answer to a question like this is always going to be "as high as you want." A recent example: two copies of Enduring Scalelord plus anything that puts a +1/+1 counter on something to get the chain started. Or are you asking what the most you can do without an infinite combo is? Dec 10, 2015 at 21:51
• That combo takes three cards: two copies of Enduring Scalelord plus absolutely any card that puts a +1/+1 counter on something. Okay, I guess you need land to play your spells too. But it's just a few cards. Dec 10, 2015 at 21:56
• See a simple example here: boardgames.stackexchange.com/questions/14437/… Dec 10, 2015 at 22:12
• Why is this question getting "Too Broad" close votes? It is not asking for a list of every infinite combo in Magic. You only need to mention one infinite combo in your answer in order to arrive at a conclusion. This is clearly answerable in a few paragraphs. Dec 10, 2015 at 22:41
• I don't think this should be closed as a duplicate, at least pointing to that question. The premise of that question implies an answer to this one, but that is not the same as the question being a duplicate. Dec 16, 2015 at 20:37

Arbitrarily large.

It's not that hard to create a combo with a small number of cards that increases a creature's power without bound.

For example:

The first two create infinite mana (use Grand Architect to make Pili-Pala blue, tap Pili-Pala for {2} with Grand Architect's ability, pay those {2} and untap Pili-Pala for 1 mana of any color, and repeat). Then you can pay {1} and remove a counter from Ghave to put 2 tokens into play (due to Doubling Season), then pay {1} and sacrifice one of those tokens to put 2 counters on Ghave (due to Doubling Season). The end result is an arbitrarily large number of +1/+1 counters on Ghave and an arbitrarily large number of tokens.

Keep in mind that you don't need infinite time (or even O(n) time) to give a creature arbitrarily large power, using this combo or just about any other. The Magic rules allow players to take shortcuts, as described in rule 719. The specific rule that is relevant here is 719.2a:

At any point in the game, the player with priority may suggest a shortcut by describing a sequence of game choices, for all players, that may be legally taken based on the current game state and the predictable results of the sequence of choices. This sequence may be a non-repetitive series of choices, a loop that repeats a specified number of times, multiple loops, or nested loops, and may even cross multiple turns. It can’t include conditional actions, where the outcome of a game event determines the next action a player takes. The ending point of this sequence must be a place where a player has priority, though it need not be the player proposing the shortcut.

• Example: A player controls a creature enchanted by Presence of Gond, which grants the creature the ability “{T}: Put a 1/1 green Elf Warrior creature token onto the battlefield,” and another player controls Intruder Alarm, which reads, in part, “Whenever a creature enters the battlefield, untap all creatures.” When the player has priority, he may suggest “I’ll create a million tokens,” indicating the sequence of activating the creature’s ability, all players passing priority, letting the creature’s ability resolve and put a token onto the battlefield (which causes Intruder Alarm’s ability to trigger), Intruder Alarm’s controller putting that triggered ability on the stack, all players passing priority, Intruder Alarm’s triggered ability resolving, all players passing priority until the player proposing the shortcut has priority, and repeating that sequence 999,999 more times, ending just after the last token-creating ability resolves.

Obviously, the example they use isn't exactly the same, but it means that I could do the same thing with the combo I described by saying "I'll create a million tokens and put a million counters on Ghave"

• I think it might be appropriate to point out in this answer that "infinite time" to play out the game is unnecessary. CR 716 contains the rules for taking shortcuts to handle repetitive loops that would create an arbitrarily large number of +1/+1 counters. Dec 10, 2015 at 23:06
• I've added a section about that Dec 10, 2015 at 23:40
• @DrunkCynic Just to clear up some potential confusion, you cannot simply "reject" a shortcut. You must either accept the shortcut, or deviate from it at a specific point. Forcing your opponent to play it out while you watch the clock run down is not an option that is available to you. Dec 17, 2015 at 15:45
• I'm slightly disappointed that at no point in this answer has Infinity Elemental been mentioned. (I'm joking but kinda not) Apr 6, 2018 at 17:18
• This post is from late 2015, long before Unstable was printed. And in general we avoid talking about silver bordered cards in answers unless they're specifically the subject of the question, because they don't really follow the rules. Apr 6, 2018 at 17:43