How do staggered infinite loops resolve?

Asked by Yesterday 1 month ago

This is a game rules question that I'm intentionally posting here because, after the ~15 hour downtime, the preview in the Rules Q&A section is showing no line breaks or text formatting and this is a pretty long post. If a mod could move it over please, I'd appreciate it.

I want to make sure I'm understanding correctly.

From MTG Tournament Rules ===code 4.4 Loop

A loop is a form of tournament shortcut that involves detailing a sequence of actions to be repeated and then performing a number of iterations of that sequence. The loop actions must be identical in each iteration and cannot include conditional actions ("If this, then that".)


If two or more players are involved in maintaining a loop within a turn, each player in turn order chooses a number of iterations to perform. The game advances through the lowest number of iterations chosen and the player who chose that number receives priority. ===endcode


So, Player 1 is the active player and controls a Spirit Mirror . Player 2 is the nonactive player and controls a Conspiracy naming Reflection, and a Frenetic Efreet .

Player 1 wants to destroy the Efreet before Player 2 gets the chance to resolve the Efreet's ability to potentially save itself. Both players can activate their abilities in response to the other player activating theirs, and wishes to keep on doing so. The modus is on the active player to not continue the loop. In this case, Player 2 gets a chance to save the Efreet before Player 1 can destroy it. Assuming we wait until Player 2's turn, if the same loop were to play out, then Player 1 (the nonactive player) would be able to destroy the Efreet before Player 2 gets the chance to save it.

Is this right?

Likewise, say Player 1 is has infinite damage in the form of an artifact that reads ": This permanent deals 1 damage to any target." And Player 2 has an artifact with ": You gain 1 life."

As long as Player 1 is the active player, they can't win the game. But when Player 2 becomes the active player, Player 1 can win the game because Player 2 is forced to decide how many iterations of the loop they're committing to before Player 1 does, and thusly 1 damage will get through when the loop resolves (and then it can be restarted)?

And if I'm all correct so far, then let's assume that Player 1 instead has a more realistic infinite damage combo in the form of Experiment Kraj , Argothian Elder with a +1/+1 counter, Ashaya, Soul of the Wild , Pemmin's Aura enchanting Kraj, Island , Prodigal Sorcerer with a +1/+1 counter. (Tap Kraj using the Elder's ability to untap Kraj and an Island, tap Kraj to deal 1 damage to any target, pay the Island's to untap Kraj with the Aura.)

Player 2 still controls the nonsense artifact with ": You gain 1 life."

In this case, regardless of who the active player is, Player 1 is unable to win the game as, in the shortcutting of the loop, Player 2 is able to activate the lifegain ability as many times as they choose in response to any of the three steps that form Player 1's combo that only deals 1 damage.

Is this all correct?

You should change your name to Tomorrow because you’re ahead of me...

May 8, 2021 6:08 p.m.

1empyrean says... #2

The non-active player will always have the last word. However, once a loop has been shortcut, it may not be restarted until the game has changed in a relevant way. (Stated on the same page of the tournament rules)

May 8, 2021 6:45 p.m.

shadow63 says... #3

I believe the game would result in a draw

May 8, 2021 9:02 p.m.

plakjekaas says... #4

Not in a draw, but the game would result in all the slow-play warnings necessary to start advancing the boardstate again.

A draw would be caused by a loop that feeds back into itself. Like a Brash Taunter enchanted with Pariah and targeted with Arcbond , with an opponent reacting to the Taunter's fight ability by flashing in a Selfless Squire . The Arcbond will try to damage all players, but neither will take damage. The Pariah deals that damage to the Taunter instead, causing the exact same thing to happen again. If nobody can remove the Taunter or the Pariah, the loop will go on forever without any advancement to the game, resulting in a draw. I actually drew a game of commander this way yesterday.

May 9, 2021 11:04 a.m.

Epidilius says... #5

Who would get the slow play warnings in this case?

May 9, 2021 12:50 p.m.

plakjekaas says... #6

I'm (or at least used to be) just a local FNM judge, so don't quote me on this ruling, but I'd say both players are intentionally not progressing the boardstate by stacking the abilities infinitely on top of each other. If none of them wants to stop, they can probably either choose to draw and play the next game, or keep stalling until they both get the warnings and game losses attached when they have 3.

May 9, 2021 4:37 p.m.

Epidilius says... #7

If we take the two artifacts example (P1 has an artifact with "0: Deal 1" and P2 has an artifact with "0: Gain 1") would a judge really give P2 a warning for not intentionally losing?

May 11, 2021 11 a.m.

1empyrean says... #8

Epidilius, I stated previously that the rules say once a loop has been shortcut, it may not be restarted until the game has changed in a relevant way. plakjekaas did say not to quote him on his way of resolving the issue, and forcing both players to take a loss doesn't really make sense.

Also, he likely hasn't had to deal with a loop of this kind very often, if ever, in any case. I know I haven't seen it come up very often.

May 11, 2021 1:19 p.m.

Epidilius says... #9

Yeah, I wasn't trying to be snarky, just genuine curiosity. Re: your post, wouldn't life loss/gain count as a relevant change to the board state?

I also imagine most players would just look at that board state and not bother getting into this kind of situation.

May 11, 2021 1:29 p.m. Edited.

plakjekaas says... #10

I suppose this is why Wizards is, or at least should be, careful with free abilities '^^ I mean ": deal 1 damage" is something that should never be printed on a card.

It's a sneaky way to gain advantage if your opponent has gathered more warnings than you in the tournament you're playing, but even that intent will be weighed if a MagicFest head judge has to rule something like this. I'd say avoid these infinite loops if you can, they're cool theorycrafts and maybe would make a fun commander goal, but in official tournaments they'll probably cause several headaches to actually resolve.

May 11, 2021 1:53 p.m.

Yesterday says... #11

It's been a little over a week and this is still in General, so respectfully, I think what I'm gonna do now is tag, uh... Rhadamanthus and Gidgetimer to bring their attention here.

May 16, 2021 3:54 a.m.

Rhadamanthus says... #12

Converted to a question in "Rules Q&A" per request.

I don't really look at any other part of the website anymore, so I wasn't aware of this until I got tagged. Feel free to do that in the future if you need help moving something again.

May 17, 2021 9:45 a.m. Edited.

Caerwyn says... #13

In the future, please remember to use the green "Mark as Answer" button when your question is resolved. As this question has been answered for several days, I have gone ahead and marked an answer on your behalf.

I'll note that you can also tag me if you need a post moved--I generally try to monitor the homepage and threads and move them over here if needed, but I must have missed this one.

May 18, 2021 11:33 p.m.

Yesterday says... #14

Caerwyn, this question hasn't really been answered. I posted this question because I'm fairly sure I understand the baseline ruling, so I gave three examples on how I think it'd play out, looking for confirmation on them.

There've been a lot of contradictory answers, and the post that you marked as the answer confirms my baseline understanding of the rule, but I still don't know I applied the ruling correctly in the given examples.


Also cheers, I'll remember about the tagging next time. Hadn't really been paying attention to who's a mod, so just tagged the first two names I recognised from the "Recently Answered" section.

May 20, 2021 7:09 a.m. Edited.

Yesterday says... Accepted answer #15

Here, in case of future people in search engines.

May 27, 2021 8:06 a.m.

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