Layer System

Comprehensive Rules §613

The Layer System

Continuous effects are applied in a strict sequence of seven layers.
Within each layer, timestamp order resolves conflicts — unless a dependency overrides it.

Principle

Layers are absolute. An effect in Layer 4 is always applied before Layer 7, regardless of which entered the battlefield first.

Interactive

Simulator

Step through layer resolution. Add or remove effects to explore interactions.

Effects in Play
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Resolution Log

Rules 613.7 & 613.8

Timestamps & Dependencies

Within each layer, effects are applied oldest-first.
Dependencies can override this ordering.

Timestamp Rules 613.7

  1. Each continuous effect has a timestamp indicating when it began to apply.
  2. A permanent’s timestamp is when it entered the battlefield or most recently changed controllers.
  3. An Aura or Equipment’s timestamp is when it became attached to its current object.
  4. A continuous effect from a resolving spell or ability timestamps at resolution.
  5. Identical timestamps resolve in APNAP order (Active Player, Non-Active Player).
  6. If an effect moves to a different layer/sublayer, it receives a new timestamp.

Dependencies 613.8

When one effect depends on another, the depended-upon effect is applied first regardless of timestamp.

Dependency Test

Effect A depends on Effect B when all three conditions hold:

  1. Both apply in the same layer and sublayer
  2. Applying B would change what A affects or does
  3. Neither is a CDA in Layer 7a

Opalescence + Humility

L4
Opalescence — non-Aura enchantments become creatures with P/T = mana value
L6
Humility — all creatures lose all abilities
L7b
Humility — all creatures have base P/T 1/1

Opalescence’s L4 makes enchantments into creatures. Humility’s L6 then strips abilities from all creatures — including Opalescence. With its ability gone, Opalescence has no L7b effect. Only Humility’s 1/1 applies. Result: both are 1/1 creatures with no abilities.

Circular Dependencies

When A depends on B and B depends on A, neither takes precedence. The system falls back to timestamp order.

Common Misconceptions

  • “Last in wins” Only within the same layer/sublayer. A newer L6 effect cannot override an older L7 effect.
  • “Removing an ability undoes earlier layers” No. L4 type changes persist even if the source ability is removed in L6.
  • “Counters are modifications” Counters (7c) and modifications (7d) are separate sublayers with distinct ordering.