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Here's an article published on Hipsters of the Coast about a 107-minute MTG Arena game. The core idea is, one player was playing a deck that had no win condition except 4 Teferi, Hero of Dominaria. The deck wins by first getting Teferi to its ultimate, cast some spells to exile all the opponent's permanents, and then use Teferi's -3 to put itself back to the library. Since the opponent can't cast spells, they'll eventually draw their entire library and lose.

At least, that's the plan. In this particular game, the opponent countered or killed all four Teferi. That leaves the player with no way to win. However, he's still able to loop Nexus of Fate to take all the turns and never lose either.

Question: if this happens in paper Magic, is the game drawn?

Allure
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  • I am unclear; which player has Nexus? The same as the Teferi player, or the opponent? – GendoIkari Feb 19 '19 at 13:57
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    Even after reading the original article, I'm having trouble following the question because of all the extra details. Is it actually simply the case that there is one player that has no cards in their library other than a Nexus of Fate, and nothing on the battlefield they can use to win, so they are simply taking infinite turns with Nexus of Fate? Is Teferi at all relevant to the situation that is actually occurring, or is that just the background of how the situation came about? – GendoIkari Feb 19 '19 at 14:04
  • @GendoIkari teferi player has no win con but can just loop nexus, taking infinite turns on which he does nothing but draw and cast nexus. – Andrew Feb 19 '19 at 15:00
  • @Andrew That makes sense, but I think the question should be reworded for simplicity. In this case, all that matters is that you have a player whose library contains only a Nexus of Fate at the start of his turn, and nothing useful he can do, who wants to infinitely cast Nexus of Fate. Teferi is irrelevant to the question. – GendoIkari Feb 19 '19 at 15:35
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    Possible duplicate of What happens in the event of a standoff in Magic? I think the fourth example, a spell that gets shuffled back into the deck when cast applies, though in that case it was both players needing to be involved in the loop. – Andrew Feb 19 '19 at 15:38
  • @Andrew I think this is different. This is a case of a single player having the ability to do something an unlimited number of times, no different than choosing to activate any other infinite combo forever. Having both players involved vs just a single player makes it a different question with a similar answer. – GendoIkari Feb 19 '19 at 15:58
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    @GendoIkari While I originally intended https://boardgames.stackexchange.com/q/45162/9999 to be about a different but related scenario, I've realized it's just a more generalized version of this question and added a case to include the scenario described here – Zags Feb 19 '19 at 16:01
  • @Zags I don't see a case there that is similar to this. All situations in that question involve both players (except the Angel/Persecutor one, which is different). – GendoIkari Feb 19 '19 at 16:04
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    @GendoIkari The case was in the answer. I have added the case to the question as well – Zags Feb 19 '19 at 16:05
  • @GendoIkari sorry for late response but I mentioned Teferi in this question because it means the player is legitimately trying to win the game. He's not playing a deck that cannot actually win (i.e. even if opponent does nothing except pass the turn from turn 1). I don't know if there are rules against playing decks that cannot win. If the standoff rules are what they are, presumably no, but anyone doing this in a casual game would quickly lose all their friends regardless of what the rules are. – Allure Jul 16 '19 at 02:43

2 Answers2

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No. If you in a situation like that in paper magic, you'll have to create a shortcut per CR:

720.1b Occasionally the game gets into a state in which a set of actions could be repeated indefinitely (thus creating a "loop"). In that case, the shortcut rules can be used to determine how many times those actions are repeated without having to actually perform them, and how the loop is broken.

Also per MTR 4.4, you can't ‘opt-out’ of shortcutting a loop:

A player may not ‘opt-out’ of shortcutting a loop, nor may they make irrelevant changes between iterations in an attempt to make it appear as though there is no loop. Once a loop has been shortcut, it may not be restarted until the game has changed in a relevant way.

The game could be drawn if both players were involved in a loop both would choose to continue indefinitely, but this is not the case:

If two or more players are involved in maintaining a loop across turns, each player chooses a number of iterations to perform, or announces their intent to continue indefinitely. If all players choose to continue indefinitely, the game is a draw.

piotrek
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    Do you mean the person looping Nexus of Fate will be forced to stop and pass the turn? – Allure Feb 19 '19 at 09:02
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    Exactly. Once their opponent has changed the game state they could loop a second time, but that would also be a finite loop. – Arcanist Lupus Feb 19 '19 at 13:01
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    Note that the loop rules technically apply in Arena too, but they haven't figured out how to implement them yet. – Arcanist Lupus Feb 19 '19 at 13:02
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    Also, a loop that can't be stopped by the players (because all the actions involved are mandatory) will cause the game to end in a draw. – Arcanist Lupus Feb 19 '19 at 13:04
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    Wow it sounds like MTG Arena has a HUGE flaw. So anytime a player can do something an unlimited number of times, instead of having you pick a number of times to repeat that loop, like you do in actual MTG, it just lets you literally keep doing it as long as you want? Sounds terrible. – GendoIkari Feb 19 '19 at 14:02
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    Nah, rather than a flaw in Arena, this is a rule that requires some human interpretation. Notice that there is no description of what constitutes a loop in the rules. Rather, it relies on humans to recognize one when they see it. It can be a very complex thing to detect through an algorithm (such as, for example, when it includes cards going into a seemingly randomized state of shuffling a deck) yet a human will be able to recognize it as such. This gets even more complicated when the player is changing irrelevant details. Basically, it's just a thing computers are no good at... – Jasper Feb 19 '19 at 14:22
  • "The game could be drawn if both players were involved in a loop both would choose to continue indefinitely" Do you mean "The game could be drawn if both players were involved in a loop that both choose to continue indefinitely"? – Acccumulation Feb 19 '19 at 17:33
  • @Gendolkari Normally you can not repeat an action indefiniately in Arena as you have a set amount of time for your turn. However Nexus gets around this as each loop gives you a new turn (and a resets your turn time). Normally Looping is really bad for the looping player, as they must preform the actions manually. So say you are able to get infinite life gain triggers with a Ajani's pridemate on the board, in paper you could pick a number and make him a 2mil/2mil, in arena you would be lucky to get him above 200/200 in the allotted time. – Malco Feb 19 '19 at 17:46
  • @piotrek You might want to adjust your answer a bit since you can't actually shortcut Nexus of Fate in paper, the card ends up in a hidden zone (since you need to shuffle it into your deck). "720.2a 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. ... It can't include conditional actions, where the outcome of a game event determines the next action a player takes...." – Malco Feb 19 '19 at 18:00
  • Would this ruling apply similarly to a player that has kismet + chronatog + stasis out? Basically that player could choose during the opponent's turn to use the chronatog ability to skip their next turn indefinitely, causing the opponent to peel through their entire deck, while simultaneously never needing to pay any upkeep on stasis. Assuming the opponent doesn't have anything that can dispel or deal damage via a discard, they would be very little they could do to counter it. – CodeMonkey Feb 19 '19 at 18:38
  • @Malco It depends on how many cards are left in your library and what repeatable methods of digging through them you have. For example, if you have a library consisting of 4 Nexus of Fate and 4 other cards, and Azcanta, the Sunken Ruin in play, then between drawing a card and activating Azcanta you are guaranteed to get a Nexus of Fate into your hand each turn. It is thus 100% predictable that you can repeat the loop indefinitely, eventually drawing the remaining 4 non-Nexus cards and having an all-Nexus library. – Douglas Feb 19 '19 at 19:30
  • @Jasper It's not necessarily true that loop detection is something that computers are inherently worse at than humans are. The problem is that MTG is Turing Complete and loop detection is equivalent to the Halting Problem which is undecidable in general. And because of its undecidability in general, there's probably just been no effort to even try to have automated loop detection in the programs, since it would be an additional time investment and it could never be perfect. – Shufflepants Feb 19 '19 at 19:48
  • @Jasper So, of course, the loop shortcutting rule in the in person rules only applies to particular loops where some one can prove that that sequence can be looped indefinitely. But there are necessarily sequences of card plays that while resulting in a loop, no one would be able to prove. It's just that these sorts for sequences are exceedingly rare in normal play and you wouldn't be able to prove that you'd identified one! – Shufflepants Feb 19 '19 at 19:51
  • @Douglas it is a bit trickier than that though, the opponent doesn't "know' that you have 4 Nexus of fate in your deck, for instance there might be 3 in your hand currently or you may only have 1 Nexus total in your decklist. Having the cards enter and exit private zones makes it pretty complicated. – Malco Feb 19 '19 at 20:09
  • @Malco In a tournament setting, that could be dealt with by calling over a judge to check your library and verify that there are few enough non-Nexus cards in it to make the loop reliable. If you start executing the loop without shortcutting, then your opponent could call over a judge instead, to check your library to determine whether shortcutting is possible (and therefore mandatory). – Douglas Feb 19 '19 at 20:28
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    Also, even if it wasn't technically a loop, the player would almost certainly be dinged for stalling unless they could prove that they have a way to win. – Arcanist Lupus Feb 20 '19 at 01:34
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You can't stall indefinitely using Nexus of Fate because it is an optional ability loop involving just you.

From the Tournament Rules section 4.4:

If one player is involved in maintaining the loop, they choose a number of iterations. The other players, in turn order, agree to that number or announce a lower number after which they intend to intervene. The game advances through the lowest number of iterations chosen and the player who chose that number receives priority.

...

A player may not 'opt-out' of shortcutting a loop, nor may they make irrelevant changes between iterations in an attempt to make it appear as though there is no loop. Once a loop has been shortcut, it may not be restarted until the game has changed in a relevant way. Proposing loops as an effort to use up time on the clock is Stalling.

In order for a loop of optional abilities to cause the game to end in a draw, it has to be a multi-turn loop involving multiple players. See What happens in the event of a standoff in Magic?.

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Zags
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