It is used on
roblox as to
say "the
fuck" and is mostly used on gacha online.
In
Natural-Selection (HL-modification) the F4 key when
pressed, takes you out of the game and into the ReadyRoom, where you can choose to join a team or just jump about. When one team is getting completely wiped out, Some players
may call out for the others to "F4!" as a way to end the game early, and sometimes, to deny the opposing team a victory.
they Have Skulks! F4! F4!