If I declare a blocking creature to my opponent's attacking creature and during combat I activated my creatures ability tapping it does that creature still take the combat damage. Or should that just be declared a blocker and negate the damage step?
Tapped blockers still deal and receive combat damage. It used to be in ages past (prior to 6th edition, so before 1999), that a tapped creature didn't deal combat damage, but that is ancient history.
Also, the combat damage step will happen if a creature is declared attacking or enters the battlefield attacking, regardless of wether there are actually any creatures left to deal combat damage when the combat damage step begins. The game skips the declare blockers step and the combat damage step, if no attacker was created during the declare attackers step.
If I declare a blocking creature to my opponent's attacking creature and during combat I activated my creatures ability tapping it does that creature still take the combat damage. Or should that just be declared a blocker and negate the damage step?
506.4b Tapping or untapping a creature that’s already been declared as an attacker or blocker doesn’t remove it from combat and doesn’t prevent its combat damage.
Also, the combat damage step will happen if a creature is declared attacking or enters the battlefield attacking, regardless of wether there are actually any creatures left to deal combat damage when the combat damage step begins. The game skips the declare blockers step and the combat damage step, if no attacker was created during the declare attackers step.
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