Community

Game Play Error — Missed Trigger

Definition

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 make it clear what the action taken or choice made is before taking any game actions (such as casting a sorcery spell or explicitly moving to the next step or phase) that can be taken only after the triggered ability should have resolved. Note that 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 prevent an opponent from taking any resulting illegal action.

•A triggered ability that affects the game state in non-visible ways: The controller must take physical action or make it clear what the action is the first time the change has an effect on the visible game state.

Once any of the above obligations has been fulfilled, or the trigger has been otherwise acknowledged, 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).

Players may not cause triggered abilities controlled by an opponent to be missed by taking game actions or otherwise prematurely advancing the game. For example, if a player draws a card during his or her draw step without allowing an opponent to demonstrate awareness of a triggered ability, the controller still has an opportunity to fulfill the appropriate obligation by doing so at that point. 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.

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.

Examples
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 his
draw step.
C. A player casts Azorius Arrester, then forgets its triggered ability by not choosing a target for it. He realizes
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. She realizes the
error when declaring blockers during the next turn.

Philosophy

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. Players 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. 

The controller of a missed triggered ability receives a Warning only if the triggered ability is usually considered detrimental for the controlling player. 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. Whether a Warning is issued or not does not affect any additional remedies that may be applicable. Failure to Maintain Game State penalties are never issued to players who did not control the ability. Judges should 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 his or her triggered abilities.

Additional Remedy

If the triggered ability specifies a default action associated with a choice made by the controller (usually "If you don't ..." or "... unless"), resolve it choosing the default option. If the triggered ability is a delayed triggered ability that changes the zone of an object, resolve it. For these two types of abilities, the opponent chooses whether to resolve the ability immediately or at the start of the next phase. These abilities do not expire and should be remedied no matter how much time has passed since they should have triggered. 

If the triggered ability creates an effect whose duration has already expired or the ability was missed prior to the current phase in the previous player's turn, 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 were not in the appropriate zone or zones 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.