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Magic: The Gathering Comprehensive Rules Changes

Masters Edition to Lorwyn (Single Change View)

General changes

Old rule (Masters Edition) New rule (Lorwyn)

Blocking Creature

A creature becomes a blocking creature when (a) it's declared as part of a legal block during the combat phase and (b) all costs to block, if any, have been paid. It remains a blocking creature until it's removed from combat, it stops being a creature, its controller changes, or the combat phase ends. Blocking creatures don't exist outside of the combat phase. See rule 309, "Declare Blockers Step."

Blocking Creature

A creature becomes a blocking creature when (a) it's declared as part of a legal block during the combat phase and (b) all costs to block, if any, have been paid. It remains a blocking creature until it's removed from combat, it stops being a creature, its controller changes, or the combat phase ends. A creature may also be put into play blocking. Blocking creatures don't exist outside of the combat phase. See rule 309, "Declare Blockers Step."