The aid attack action is a standard action that allows a character to grant a bonus to another character's attack roll against a target.[PH:287][RC:238] The character chooses an adjacent enemy, and an ally. Before the end of the character's next turn, the next time the ally makes an attack roll against the enemy, the ally receives a +2 bonus to that attack roll. A single character cannot use the aid attack action to affect the same attack roll more than once. Under normal circumstances, up to four characters can each use an aid attack action to affect the same attack roll.