Déliquescence soudaine et Fraction de seconde

112.12. An effect that sets an object’s characteristic, or simply states a quality of that object, is different from an ability granted by an effect. When an object “gains” or “has” an ability, that ability can be removed by another effect. If an effect defines a characteristic of the object (“[permanent] is [characteristic value]”), it’s not granting an ability. (See rule 604.3.) Similarly, if an effect states a quality of that object (“[creature] can’t be blocked,” for example), it’s neither granting an ability nor setting a characteristic.

Example: Muraganda Petroglyphs reads, “Creatures with no abilities get +2/+2.” A Runeclaw Bear (a creature with no abilities) enchanted by an Aura that says “Enchanted creature has flying” would not get +2/+2. A Runeclaw Bear enchanted by an Aura that says “Enchanted creature is red” or “Enchanted creature can’t be blocked” would get +2/+2.

613. Interaction of Continuous Effects

613.1. The values of an object’s characteristics are determined by starting with the actual object. For a card, that means the values of the characteristics printed on that card. For a token or a copy of a spell or card, that means the values of the characteristics defined by the effect that created it. Then all applicable continuous effects are applied in a series of layers in the following order:

613.1a Layer 1: Copy effects are applied. See rule 706, “Copying Objects.”

613.1b Layer 2: Control-changing effects are applied.

613.1c Layer 3: Text-changing effects are applied. See rule 612, “Text-Changing Effects.”

613.1d Layer 4: Type-changing effects are applied. These include effects that change an object’s card type, subtype, and/or supertype.

613.1e Layer 5: Color-changing effects are applied.
613.1f Layer 6: Ability-adding effects, ability-removing effects, and effects that say an object can’t

have an ability are applied.
613.1g Layer 7: Power- and/or toughness-changing effects are applied.

613.2. Within layers 1–6, apply effects from characteristic-defining abilities first (see rule 604.3), then all other effects in timestamp order (see rule 613.6). Note that dependency may alter the order in which effects are applied within a layer. (See rule 613.7.)

613.3. Within layer 7, apply effects in a series of sublayers in the order described below. Within each sublayer, apply effects in timestamp order. (See rule 613.6.) Note that dependency may alter the order in which effects are applied within a sublayer. (See rule 613.7.)

613.3a Layer 7a: Effects from characteristic-defining abilities that define power and/or toughness are applied. See rule 604.3.

613.3b Layer 7b: Effects that set power and/or toughness to a specific number or value are applied. Effects that refer to the base power and/or toughness of a creature apply in this layer.

613.3c Layer 7c: Effects that modify power and/or toughness (but don’t set power and/or toughness to a specific number or value) are applied.

613.3d Layer 7d: Power and/or toughness changes from counters are applied. See rule 121, “Counters.”

613.3e Layer 7e: Effects that switch a creature’s power and toughness are applied. Such effects take the value of power and apply it to the creature’s toughness, and take the value of toughness and apply it to the creature’s power.

Example: A 1/3 creature is given +0/+1 by an effect. Then another effect switches the creature’s power and toughness. Its new power and toughness is 4/1. A new effect gives the creature +5/+0. Its “unswitched” power and toughness would be 6/4, so its actual power and toughness is 4/6.

Example: A 1/3 creature is given +0/+1 by an effect. Then another effect switches the creature’s power and toughness. Its new power and toughness is 4/1. If the +0/+1 effect ends before the switch effect ends, the creature becomes 3/1.
Example: A 1/3 creature is given +0/+1 by an effect. Then another effect switches the creature’s power and toughness. Then another effect switches its power and toughness again. The two switches essentially cancel each other, and the creature becomes 1/4.

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

Example: An effect that reads “Wild Mongrel gets +1/+1 and becomes the color of your choice until end of turn” is both a power- and toughness-changing effect and a color- changing effect. The “becomes the color of your choice” part is applied in layer 5, and then the “gets +1/+1” part is applied in layer 7c.

Example: Act of Treason has an effect that reads “Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.” This is both a control- changing effect and an effect that adds an ability to an object. The “gain control” part is applied in layer 2, and then the “it gains haste” part is applied in layer 6.

Example: An effect that reads “All noncreature artifacts become 2/2 artifact creatures until end of turn” is both a type-changing effect and a power- and toughness-setting effect. The type-changing effect is applied to all noncreature artifacts in layer 4 and the power- and toughness-setting effect is applied to those same permanents in layer 7b, even though those permanents aren’t noncreature artifacts by then.

Example: Svogthos, the Restless Tomb, is on the battlefield. An effect that says “Until end of turn, target land becomes a 3/3 creature that’s still a land” is applied to it (layers 4 and 7b). An effect that says “Target creature gets +1/+1 until end of turn” is applied to it (layer 7c), making it a 4/4 land creature. Then while you have ten creature cards in your graveyard, 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.” (layers 4, 5, and 7b). It becomes an 11/11 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 4/4 land creature again.

613.6. Within a layer or sublayer, determining which order effects are applied in is usually done using a timestamp system. An effect with an earlier timestamp is applied before an effect with a later timestamp.

[613.6a-613.6j]

613.7. Within a layer or sublayer, determining which order effects are applied in is sometimes done using a dependency system. If a dependency exists, it will override the timestamp system.

[613.7a-613.7c]

116. Timing and Priority

116.1. Unless a spell or ability is instructing a player to take an action, which player can take actions at any given time is determined by a system of priority. The player with priority may cast spells, activate abilities, and take special actions.

116.1a A player may cast an instant spell any time they have priority. A player may cast a noninstant spell during their main phase any time they have priority and the stack is empty.

116.1b A player may activate an activated ability any time they have priority.

116.1c A player may take some special actions any time they have priority. A player may take other special actions during their main phase any time they have priority and the stack is empty. See rule 115, “Special Actions.”

116.1d A player may activate a mana ability whenever they have priority, whenever they have casting a spell or activating an ability that requires a mana payment, or whenever a rule or effect asks for a mana payment (even in the middle of casting or resolving a spell or activating or resolving an ability).

116.2. Other kinds of abilities and actions are automatically generated or performed by the game rules, or are performed by players without receiving priority.

[116.2a-116.2e]

116.3b The active player receives priority after a spell or ability (other than a mana ability) resolves.

116.3c If a player has priority when they cast a spell, activate an ability, or take a special action, that player receives priority afterward.

116.3d If a player has priority and chooses not to take any actions, that player passes. If any mana is in that player’s mana pool, they announce what mana is there. Then the next player in turn order receives priority.

116.4. If all players pass in succession (that is, if all players pass without taking any actions in between passing), the spell or ability on top of the stack resolves or, if the stack is empty, the phase or step ends.

[116.5-116.7]