Regenerate

[Destore117]

When a creature regenerates what happens? Is it tapped or untapped? Or does that depend on how it was when you paid the regenerate cost?

[abstractApathist]

Regenerating something meand the next time it would be destroyed, instead remove all damage on it, tap it and if it's an attacking or blocking creature remove it from combat.

701.12a: If the effect of a resolving spell or ability regenerates a permanent, it creates a replacement effect that protects the permanent the next time it would be destroyed this turn. In this case, "Regenerate [permanent]" means "The next time [permanent] would be destroyed this turn, instead remove all damage marked on it and tap it. If it's an attacking or blocking creature, remove it from combat."

RESOLVED