A) An FPS (primarily
multiplayer) gun that requires skill to get results. Maybe it only deals massive damage on headshots, maybe it has very little ammo, maybe it's
particularly short ranged, but regardless, simply holding down the trigger while aiming in
the general direction of another will get you killed, while playing to the weapon's strengths will allow you to dominate.
B) Sarcastic - "oh yeah, the missile launcher with a huge damage radius is a total skill cannon".