Magic: The Gathering Comprehensive Rules

controller intends to exercise the ability’s option or not. The choice is made when the ability resolves. Likewise, triggered abilities that have an effect “unless” something is true or a player chooses to do something will go on the stack normally; the “unless” part of the ability is dealt with when the ability resolves.

410.6. An ability triggers only once each time its trigger event occurs. However, it can trigger repeatedly if one event contains multiple occurrences. See also rule 410.9.

Example: A permanent has an ability whose trigger condition reads, “Whenever a land is put into a graveyard from play, . . . .” If someone plays a spell that destroys all lands, the ability will trigger once for each land put into the graveyard during the spell’s resolution.

410.7. An ability triggers only if its trigger event actually occurs. An event that’s prevented or replaced won’t trigger anything.

Example: An ability that triggers on damage being dealt won’t trigger if all the damage is prevented.

410.8. Triggered abilities with a condition directly following the trigger event (for example, “When/Whenever/At [trigger], if [condition], [effect]”), check for the condition to be true as part of the trigger event; if it isn’t, the ability doesn’t trigger. The ability checks the condition again on resolution. If it’s not satisfied, the ability does nothing. Note that this mirrors the check for legal targets. Note that this rule doesn’t apply to any triggered ability with an “if” condition elsewhere within its text. This rule is referred to as the “intervening ‘if’ clause” rule.

410.9. Some abilities trigger when creatures block or are blocked in combat. (See rules 306-311 and rule 500, “Legal Attacks and Blocks.”) They may trigger once or repeatedly, depending on the wording of the ability.

410.9a An ability that reads “Whenever [this creature] blocks, . . .” triggers only once each combat for that creature, even if it blocks multiple creatures. It triggers only if the creature is declared as a blocker.

410.9b An ability that reads “Whenever [this creature] blocks a creature, . . .” triggers once for each attacking creature the creature with the ability blocks. It triggers only if the creature is declared as a blocker.

410.9c An ability that reads “Whenever [this creature] becomes blocked, . . .” triggers only once each combat for that creature, even if it’s blocked by multiple creatures. It will also trigger if an effect causes a creature to block the attacking creature, but only if it hadn’t already been blocked that combat. It will trigger if the creature becomes blocked by an effect rather than a creature.

410.9d An ability that reads “Whenever a creature blocks [this creature], . . .” triggers once for each creature that blocks the named creature. It will also trigger if an effect causes a creature to block the attacking creature, even if it had already been blocked that combat. It won’t trigger if the creature becomes blocked by an effect rather than a creature.

410.9e If an ability triggers when a creature blocks or becomes blocked by a particular number of creatures, the ability triggers if the creature blocks or is blocked by that many creatures when the attack or block declaration is made. Effects that add or remove blockers can cause such abilities to trigger. This also applies to abilities that trigger on a creature blocking or being blocked by at least a certain number of creatures.

410.10. Trigger events that involve objects changing zones are called “zone-change triggers.” Many abilities with zone-change triggers attempt to do something to that object after it changes zones. During resolution, these abilities look for the object in the zone that it moved to. If the object is unable to be found in the zone it went to, the part of the ability attempting to do something to the object will fail to do anything. The ability could be unable to find the object because the object never entered the specified zone, because it left the zone before the ability resolved, or because it is in a zone that is hidden from a player, such as a library or an opponent’s hand. (This rule applies even if the object leaves the zone and returns again before the ability resolves.) The most common types of zone-change triggers are comes-into-play triggers and leaves-play triggers.

410.10a Comes-into-play abilities trigger when a permanent enters the in-play zone. These are written, “When [this object] comes into play, . . . “ or “Whenever a [type] comes into play, . . .” Each time an event puts one or more permanents into play, all permanents in play (including the newcomers) are checked for any comes- into-play triggers that match the event.

410.10b Continuous effects that modify characteristics of a permanent do so the moment the permanent is in play (and not before then). The permanent is never in play with its unmodified characteristics. Continuous effects don’t apply before the permanent is in play, however (see rule 410.10e).

Example: If an effect reads “All lands are creatures” and a land card is played, the effect makes the land card into a creature the moment it enters play, so it would trigger abilities that trigger when a creature comes into play. Conversely, if an effect reads “All creatures lose all abilities” and a creature card with a comes-into-play triggered ability enters play, that effect will cause it to lose its abilities the moment it enters play, so the comes-into-play ability won’t trigger.

410.10c Leaves-play abilities trigger when a permanent leaves the in-play zone. These are written as, but aren’t limited to, “When [this object] leaves play, . . .” or “Whenever [something] is put into a graveyard from play, . . . .” An ability that attempts to do something to the card that left play checks for it only in the first zone that it went to.

410.10d Normally, objects that exist immediately after an event are checked to see if the event matched any trigger conditions. Continuous effects that exist at that time are used to determine what the trigger conditions are and what the objects involved in the event look like. However, some triggered abilities must be treated specially because the object with the ability may no longer be in play, no longer be in a zone visible to all players, or no longer be controlled by the appropriate player. The game has to “look back in time” to determine if these abilities trigger. Abilities that trigger specifically when an object leaves play, when an object leaves any visible zone for a hidden one, or when a player loses control of an object will trigger based on their existence, and the appearance of objects, prior to the event rather than afterward.

Example: Two creatures are in play along with an artifact that has the ability “Whenever a creature is put into a graveyard from play, you gain 1 life.” Someone plays a spell that destroys all artifacts, creatures, and enchantments. The artifact’s ability triggers twice, even though the artifact goes to its owner’s graveyard at the same time as the creatures.