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Magic: The Gathering Comprehensive Rules Changes

Guildpact to Dissension (Single Change View)

General changes

Old rule (Guildpact) New rule (Dissension)

309.3.

Abilities that trigger on a creature blocking or becoming blocked trigger only at the point the creature blocks or becomes blocked. They will not trigger if a creature blocks or becomes blocked, and then the characteristics of that creature are changed to match the ability's trigger condition.

Example: A creature has the ability "Whenever this creature becomes blocked by a white creature, destroy that creature at end of combat." If that creature is blocked by a black creature that is later turned white, the ability will not trigger.

309.3.

Abilities that trigger on a creature blocking trigger only at the point the creature is declared as a blocker. They will not trigger if a creature blocks, and then that creature's characteristics change to match the ability's trigger condition. They will not trigger if a creature is put into play blocking.