417. One-Shot Effects

417.1. A one-shot effect does something just once and doesn’t have a duration. Examples include damage dealing, destruction of permanents, and moving objects between zones.

417.2. Some one-shot effects instruct a player to do something later in the game (usually at a specific time) rather than when they resolve. This kind of effect actually creates a new ability that waits to be triggered. (See rule 404.4.)

418. Continuous Effects

418.1. A continuous effect modifies characteristics of objects or modifies the rules of the game for a fixed or indefinite period. A continuous effect may be generated by the resolution of a spell or ability or by a static ability of an object.

418.2. Continuous effects that modify characteristics of permanents do so simultaneously with the permanent coming into play. They don’t wait until the permanent is in play and then change it. Because such effects apply as the permanent comes into play, apply them before determining whether the permanent will cause an ability to trigger when it comes into play.

418.3. Continuous Effects from Spells or Abilities

418.3a A continuous effect generated by the resolution of a spell or ability lasts as long as stated by the spell or ability creating it (such as “until end of turn”). If no duration is stated, it lasts until the end of the game.

418.3b Continuous effects from spells, activated abilities, and triggered abilities that modify the characteristics or change the controller of one or more objects don’t affect objects that weren’t affected when the continuous effect began. Note that these work differently than continuous effects from static abilities. Continuous effects that don’t modify characteristics or change the controller of objects modify the rules of the game, so they can affect objects that weren’t affected when the continuous effect began.

Example: An effect that reads “All white creatures get +1/+1 until end of turn” gives the bonus to all permanents that are white creatures when the spell or ability resolves-even if they change color later-and doesn’t affect those that come into play or turn white afterward.

Example: An effect that reads “Prevent all damage creatures would deal this turn” doesn’t modify any object’s characteristics, so it’s modifying the rules of the game. That means the effect will apply even to damage from creatures that weren’t in play when the continuous effect began. It also affects damage from permanents that become creatures later in the turn.

418.3c If a resolving spell or ability that creates a continuous effect contains a variable, the value of that variable is determined only once, on resolution. See rule 413.2f.

418.3d Some effects from activated or triggered abilities have durations worded “as long as . . . .” If the “as long as” duration ends between the end of playing the activated ability or putting the triggered ability onto the stack and the moment when the effect would first be applied, the effect does nothing. It doesn’t start and immediately stop again, and it doesn’t last forever.

Example: Endoskeleton is an artifact with an activated ability that reads “{2}, {T}: Target creature gets +0/+3 as long as Endoskeleton remains tapped.” If you play this ability and then Endoskeleton becomes untapped before the ability resolves, it does nothing, because its duration-remaining tapped-was over before the effect began.

418.4. Continuous Effects from Static Abilities

418.4a A continuous effect generated by a static ability isn’t “locked in”; it applies at any given moment to whatever its text indicates.

418.4b The effect applies at all times that the permanent generating it is in play or the object generating it is in the appropriate zone.

Example: A permanent with the static ability “All white creatures get +1/+1” generates an effect that continuously gives +1/+1 to each white creature in play. If a creature becomes white, it gets this bonus; a creature that stops being white loses it. A creature spell that would normally create a 1/1 white creature instead creates a 2/2 white creature. The creature doesn’t come into play as 1/1 and then change to 2/2.

418.5. Interaction of Continuous Effects

418.5a The values of an object’s characteristics are determined by starting with the actual object, then applying continuous effects in a series of layers in the following order: (1) copy effects (see rule 503, “Copying Objects”); (2) control-changing effects; (3) text-changing effects; (4) type-, subtype-, and supertype-changing effects; (5) all other continuous effects, except those that change power and/or toughness; and (6) power– and/or toughness-changing effects.

Inside each layer from 1 through 5, apply effects from characteristic-setting abilities first, then all other effects. Inside layer 6, apply effects in a series of sublayers in the following order: (6a) effects from characteristic-setting abilities; (6b) all other effects not specifically applied in 6c, 6d, or 6e; (6c) changes from counters; (6d) effects from static abilities that modify power and/or toughness but don’t set power and/or toughness to a specific number or value; and (6e) effects that switch a creature’s power and toughness. See also the rules for timestamp order and dependency (rules 418.5b-418.5g).

Example: Crusade is an enchantment that reads “White creatures get +1/+1.” Crusade and a 2/2 black creature are in play. If an effect then turns the creature white, it gets +1/+1 from Crusade, becoming 3/3. If the creature’s color is later changed to red, Crusade’s effect stops applying to it, and it will return to being a 2/2.

Example: Gray Ogre, a 2/2 creature, is in play. An effect puts a +1/+1 counter on it, making it 3/3. An effect that says “Target creature gets +4/+4 until end of turn” is applied to it, making it 7/7. An enchantment that says “Creatures you control get +0/+2” enters play, making it a 7/9. An effect that says “Target creature becomes 0/1 until end of turn” is applied to it, making it a 1/4 (0/1, plus +1/+1 from the counter, plus +0/+2 from the enchantment).

Example: Svogthos, the Restless Tomb, is in play. An effect that says “Until end of turn, target land becomes a 3/3 creature that’s still a land” is applied to it. An effect that says “Target creature gets +1/+1 until end of turn” is applied to it, making it a 4/4 land creature. Then you activate Svogthos’s ability (“Until end of turn, Svogthos, the Restless Tomb becomes a black and green Plant Zombie creature with ‘This creature’s power and toughness are each equal to the number of creature cards in your graveyard.’ It’s still a land.”) while you have ten creature cards in your graveyard. It becomes a 10/10 land creature. If a creature card enters or leaves your graveyard, Svogthos’s power and toughness will be modified accordingly. If the first effect is applied to it again, it will become a 3/3 land creature again.

418.5b If an effect should be applied in different layers, the parts of the effect each apply in their appropriate layers. If an effect starts to apply in one layer, it will continue to be applied to the same set of objects in each other applicable layer, even if the ability generating the effect is removed during this process.