701.10. Fight 701.10a A spell or ability may instruct a creature to fight another creature or it may instruct two creatures to fight each other. Each of those creatures deals damage equal to its power to the other creature.
701.10b If a creature instructed to fight is no longer on the battlefield or is no longer a creature, no damage is dealt. If a creature is an illegal target for a resolving spell or ability that instructs it to fight, no damage is dealt.
701.10c If a creature fights itself, it deals damage equal to its power to itself twice.
701.10d The damage dealt when a creature fights isn't combat damage.