Instant, 2R (3)
Common
Target creature gets +3/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)
"Since when did ‘AIIIEEEE!' become a negotiation tactic?"
—Nikou, Joraga bard
Illus. Matt Cavotta

10/1/2009: If a creature doesn't have first strike, granting it first strike after combat damage has been dealt in the first combat damage step won't prevent it from dealing combat damage. It will still assign and deal its combat damage in the second combat damage step.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern