Fight is a keyword action introduced in Innistrad which represents a mechanic originally introduced with the Land Arena, though slightly altered. The word appears in a phrase like "[Cardname] and target creature fight." and it means that both creatures deal damage equal to their Power to each other.
- The damage is dealt simultaneously, and it is dealt by the creatures themselves, so abilities like deathtouch, lifelink, and infect will work as normal.
- Damage dealt while fighting is not combat damage, so abilities like first strike won't have any effect.
- Fighting doesn't cause the creatures to become tapped.
- Only creatures can fight.
- No more than two creatures can fight.
- If a creature somehow fights itself, it will deal damage to itself equal to its power twice simultaneously.
A few old cards with the same functionality will receive updated Oracle wording using the new terminology. Cards with similar, but not identical, functionality will not use the word "fight."