A backfucker is a player who will stab u in the back even if u r in the same team as long if he will get better from it. U c backfuckers in evey kinda off game also see buttfucker
Backfucker:im all out of ammo!
Teammate:u shouldt had saved some.
Backfucker: Woh look over there!!!
Teamate:huh theres nothing there!
~backfucker stabs teammate to death and takes his ammo~
Backfucker:yay ammo Teammate:u backfucker!