Area of Effect (AoE or AOE) is damage which affects more than one enemy. In League of Angels: Fire Raiders, this may be all Heroes on the enemy's team, all of them in the Front or Back Lines, both heroes in the Top, Middle, or Bottom rows, or some other combination (even random selection of more than one target).
AoE damage is especially effective in damage based Gameplay activities like the Gold Trial, Wharf boss, etc.
AoE Heroes and AoE Angels should list the Heroes and Angels (respectively) who deal AoE damage.