Circle of Protection: White

{1}: The next time a white source of your choice would deal damage to you this turn, prevent that damage.

30th Anniversary Edition

Eighth Edition

Seventh Edition

Can be used even when there is no damage to prevent. It prevents the next damage (if any) from the source this turn.

A source of damage is a permanent, a spell on the stack (including one that creates a permanent), or any object referred to by an object on the stack. A source doesn’t need to be capable of dealing damage to be a legal choice.