IPG 2.1 Game Play Error — Missed Trigger


A triggered ability triggers, but the player controlling the ability doesn’t demonstrate awareness of the trigger’s existence the first time that it would affect the game in a visible fashion.

The point by which the player needs to demonstrate this awareness depends on the impact that the trigger would have on the game:

  • A triggered ability that requires its controller to choose targets (other than ‘target opponent’), modes, or other choices made when the ability is put onto the stack: The controller must announce those choices before they next pass priority.
  • A triggered ability that causes a change in the visible game state (including life totals) or requires a choice upon resolution: The controller must take the appropriate physical action or acknowledge the specific trigger before taking any game actions (such as casting a sorcery spell or explicitly taking an action in the next step or phase) that can be taken only after the triggered ability should have resolved.

    Note that passing priority, casting an instant spell or activating an ability doesn’t mean a triggered ability has been forgotten, as it could still be on the stack.
  • A triggered ability that changes the rules of the game: The controller must acknowledge the trigger or stop an opponent who tries to take any resulting illegal action.
  • A triggered ability that affects the game state in non-visible ways: The controller must make the change known by the first time the change has an effect on the visible game state.

Once any of the above obligations has been fulfilled, further problems are treated as a Game Play Error — Game Rule Violation.

Triggered abilities that do nothing except create delayed triggered abilities automatically resolve without requiring acknowledgment. Awareness of the resulting delayed trigger must be demonstrated at the appropriate point.

Triggered abilities that do nothing except create one or more copies of a spell or ability (such as storm or cipher) automatically resolve, but awareness of the resulting objects must be demonstrated using the same requirements as described above (even though the objects may not be triggered abilities).

If a triggered ability would have no impact on the game, it’s not an infraction to fail to demonstrate awareness of it.

For example, if the effect of a triggered ability instructs its controller to sacrifice a creature, a player who controls no creatures isn’t required to demonstrate awareness of the ability.

Similarly, a player demonstrating awareness of an optional trigger with no visible effect is assumed to have made the affirmative choice unless the opponent responds.

Judges do not intervene in a missed trigger situation unless they intend to issue a Warning or have reason to suspect that the controller is intentionally missing their triggered abilities.

A player controlling another player is responsible for that player’s triggers in addition to their own.


  • A. Knight of Infamy (a 2/1 creature with exalted) attacks alone. Its controller says “Take two.”
  • B. A player forgets to remove the final time counter from a suspended spell and then draws a card during their draw step.
  • C. A player casts Manic Vandal, then forgets its triggered ability by not choosing a target for it. They realize this only after casting another spell.
  • D. A player forgets to exile the Angel token created by Geist of Saint Traft at end of combat. They realize the error when declaring blockers during the next turn.


Triggered abilities are common and invisible, so players should not be harshly penalized when forgetting about one.

Players are expected to remember their own triggered abilities; intentionally ignoring one may be Unsporting Conduct — Cheating (unless the ability would have no impact on the game as described above).

Even if an opponent is involved in the announcement or resolution of the ability, the controller is still responsible for ensuring the opponents make the appropriate choices and take the appropriate actions. Opponents are not required to point out triggered abilities that they do not control, though they may do so if they wish.

Triggered abilities are assumed to be remembered until otherwise indicated, and the impact on the game state may not be immediately apparent.

The opponent’s benefit is in not having to point out triggered abilities, although this does not mean that they can cause triggers to be missed.

If an opponent requires information about the precise timing of a triggered ability or needs details about a game object that may be affected by a resolved triggered ability, that player may need to acknowledge that ability’s existence before its controller does.

A player who makes a play that may or may not be legal depending on whether an uncommunicated trigger has been remembered has not committed an infraction; their play either succeeds, confirming that the trigger has been missed, or is rewound.

Players may not cause triggered abilities controlled by an opponent to be missed by taking game actions or otherwise prematurely advancing the game.

During an opponent’s turn, if a trigger’s controller demonstrates awareness of the trigger before they take an active role (such as taking an action or explicitly passing priority), the trigger is remembered.

The Out-of-Order Sequencing rules (MTR section 4.3) may also be applicable, especially as they relate to batches of actions or resolving items on the stack in an improper order.

Additional Remedy

Three types of triggered abilities do not expire and resolve immediately if they are discovered:

  • A triggered ability that specifies a default action associated with a choice made by the controller (usually “If you don’t …” or “… unless”). The opponent may choose not to resolve this trigger. Otherwise the default action must be chosen.
  • An enters-the-battlefield trigger of an Aura that affects only the enchanted permanent and causes a visible change to that permanent.
  • A delayed triggered ability that changes the zone of one or more objects defined when the ability was created. For this trigger, the opponent chooses whether to resolve the ability the next time a player would get priority or when a player would get priority at the start of the next phase.

Abilities consisting of an action followed by “when you do” in the same ability are considered communicated by the announcement of the action. This is most commonly the case for exert and similar abilities.  

If the ability was missed prior to the current phase in the previous turn, instruct the players to continue playing.

If the triggered ability created an effect whose duration has already expired, instruct the players to continue playing.

If the triggered ability isn’t covered by the previous two paragraphs, the opponent chooses whether the triggered ability is added to the stack.

If it is, it’s inserted at the appropriate place on the stack if possible or on the bottom of the stack.

No player may make choices involving objects that would not have been legal choices when the ability should have triggered.

For example, if the ability instructs a player to sacrifice a creature, that player can’t sacrifice a creature that wasn’t on the battlefield when the ability should have triggered.


If the triggered ability is usually considered detrimental for the controlling player the penalty is a Warning.

The current game state is not a factor in determining this, though symmetrical abilities (such as Howling Mine) may be considered usually detrimental or not depending on who is being affected.