Instant, G (1)
Common
Prevent all combat damage that would be dealt this turn.
Illus. John Avon

10/1/2009: Fog has no effect on damage that's already been dealt.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Standard (Type 2)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern