Friendly fire or non-hostile fire, a term originally adopted by the United States military, is fire from allied or friendly forces, as opposed to fire coming from enemy forces or enemy fire. A friendly fire incident (fratricide), is when allied soldiers or their artillery, base camp, vehicles, etc. are attacked and damaged by friendly fireRegan, G. Backfire: a history of friendly fire from ancient warfare to the present day. Robson Books, 2002. which may be deliberate or accidental (e.g. missing the enemy and hitting "friendlies"). Friendly fire is one kind of collateral damage. The term friendly fire is frequently used as a euphemism in military culture and frequently seen as an oxymoron. The term is also used in many video games for a setting which determines if players in the same team can damage and kill each other. The British military refer to these incidents as