#1 The Art of Avoiding Fights, taught by Aikido practitioners also. Simple stuff like, take a step back, don't walk into dark alleyways, don't flash your jewelry, Diffuse the tension, negotiate, intimidate, run away.
#2 Running Away - Used by Samurai. When faced with a huge group of enemies, the Samurai runs, as they run, the group is scattered according the the fitness of the enemies, turn around, kill one or two and continue running, eventually they will give up or you can go back and kill them. I propose to take it to the ultimate step, just keep running.
#3 My Gun is bigger than your Gun. Pretty simple, if they have black belt, you have gun, if they have gun you have machine gun etc etc. Until all humans die from a black hole generator weapon.