3. Ninjutsu
A quick straw poll in the WhatCulture office reveals that a lot of people apparently think ninjitsu is not a real thing. Ninjutsu is a real thing. Everybody has an image of the classic "ninja" in their head - dressed all in black, superhuman reaction times and perhaps a vaguely camp fighting style. Real life ninjas, however, fought dirty, and that's if they fought at all. The ninjas were assassins and true guerilla warriors as opposed to soldiers or out-and-out fighters. They actually spent a lot of their time distracting their enemies and running away, viewing the practice of sword swinging and punch throwing to be a lower art (lookin' at you, samurais). They also dressed in navy blue as opposed to black, to give them better camouflage in low light. Ninjutsu involved training in free running, disguise, escape, concealment, archery, and medicine as well as a vast arsenal of weapons designed to kill you from as far away as possible. The real reason than ninjas are "invisible" assassins is probably because they're actually miles away by the time you hit the floor.