The [b]V[/b]ault-Tec [b]A[/b]ssisted [b]T[/b]argeting [b]S[/b]ystem from [[fallout_(series)|Fallout]]. Indicated in images highlighting appendages of the body, usually with a number tagged on each limb representative of the player character's hit chance.
v.a.t.s. (fallout)