On the whole, most people use martial arts as a form of self-defense rather than killing. Rarely do practitioners of judo or Jeet Kune Do walk into a bar and start wrecking shop outside of the movies, but they definitely know a few dangerous martial arts moves that can strike a killing blow. Most of the killer martial arts moves covered here never get taught in basic martial arts classes; in fact many of them have either been phased out or only get used by the military for hand-to-hand combat. If you enjoy martial arts, or the MMA, you also won’t be seeing any of these techniques in a sanctioned match because many of them are banned for good reason; if performed incorrectly each hold, attack, and technique covered here can easily cause permanent damage, or simply kill someone.
While most well trained martial artists probably know how to do many of these moves, they won't pull them out in a match, or even in a street fight. Even still, it must be good to know that you have a literal killer move in your back pocket at all times.