613.8. One continuous effect can override another. Sometimes the results of one effect determine
whether another effect applies or what another effect does.
Example: Two effects are affecting the same creature: one from an Aura that says
“Enchanted creature has flying” and one from an Aura that says “Enchanted creature loses
flying.” Neither of these depends on the other, since nothing changes what they affect or
what they’re doing to it. Applying them in timestamp order means the one that was
generated last “wins.” The same process would be followed, and the same result reached, if
either of the effects had a duration (such as “Target creature loses flying until end of turn”)
or came from a non-Aura source (such as “All creatures lose flying”).
Example: One effect reads, “White creatures get +1/+1,” and another reads, “Enchanted
creature is white.” The enchanted creature gets +1/+1 from the first effect, regardless of its
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,
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.