Class 4 – Interaction of continuous effects (CR613)

Last updated: 02 August 2017

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Layers:

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:

  • Layer 1: Copy effects are applied.
  • Layer 2: Control-changing effects are applied.
  • Layer 3: Text-changing effects are applied.
  • Layer 4: Type-changing effects are applied. These include effects that change an object’s card type, subtype, and/or supertype.
  • Layer 5: Color-changing effects are applied.
  • Layer 6: Ability-adding effects, ability-removing effects, and effects that say an object can’t have an ability are applied.
  • Layer 7: Power- and/or toughness-changing effects are applied.

Within layers 1–6, apply effects from characteristic-defining abilities first, then all other effects in timestamp order. Within layer 7, apply effects in a series of sublayers in the order described below. Within each sublayer, apply effects in timestamp order:

– 7a: Effects from characteristic-defining abilities that define power and/or toughness are applied.

– 7b: Effects that set power and/or toughness to a specific number or value are applied.

– 7c: Effects that modify power and/or toughness are applied.

– 7d: Power and/or toughness changes from counters are applied.

– 7e: Effects that switch a creature’s power and toughness are applied.

The application of continuous effects as described by the layer system is continually and automatically performed by the game. All resulting changes to an object’s characteristics are instantaneous.

Timestamp:

If an effect should be applied in different layers and/or sublayers, the parts of the effect each apply in their appropriate ones. 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.

  • A continuous effect generated by a static ability has the same timestamp as the object the static ability is on, or the timestamp of the effect that created the ability, whichever is later.
  • A continuous effect generated by the resolution of a spell or ability receives a timestamp at the time it’s created.
  • An object receives a timestamp at the time it enters a zone.
  • An Aura, Equipment, or Fortification receives a new timestamp at the time it becomes attached to an object or player.
  • A permanent receives a new timestamp at the time it turns face up or face down
  • A double-faced permanent receives a new timestamp at the time it transforms.
  • If two or more objects would receive a timestamp simultaneously, such as by entering a zone simultaneously or becoming attached simultaneously, the active player determines their relative timestamp order at that time.

Dependency:

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.

An effect is said to “depend on” another if

(a) it’s applied in the same layer (and, if applicable, sublayer) as the other effect

(b) applying the other would change the text or the existence of the first effect, what it applies to, or what it does to any of the things it applies to

(c) neither effect is from a characteristic-defining ability or both effects are from characteristic-defining abilities.

Otherwise, the effect is considered to be independent of the other effect.

An effect dependent on one or more other effects waits to apply until just after all of those effects have been applied. If multiple dependent effects would apply simultaneously in this way, they’re applied in timestamp order relative to each other. If several dependent effects form a dependency loop, then this rule is ignored and the effects in the dependency loop are applied in timestamp order.

One continuous effect can override another. Sometimes the results of one effect determine whether another effect applies or what another effect does.

Players and Rules:

Some continuous effects affect players rather than objects. For example, an effect might give a player protection from red. All such effects are applied in timestamp order after the determination of objects’ characteristics.

Some continuous effects affect game rules rather than objects. For example, effects may modify a player’s maximum hand size, or say that a creature must attack this turn if able. These effects are applied after all other continuous effects have been applied.