Jujitsu is a Eastern martial art including basically weaponless methods, but also the use of some weapons. Specifically, it teaches unarmed techniques of combating an opponent who is armed. Like many mixed martial arts, many different forms and styles of jujitsu have evolved over the centuries. Jujitsu is a good self-defense martial arts to learn for many reasons. Second, you find out how to immobilize an attacker without necessarily hurting them. Third, it teaches as escalation of force.

First, re self-defense from a mugger or rapist, the longer you stay to battle, the bigger the chance that the attacker will overwhelm you (especially since criminal tends to travel in packs, or at least pairs). Therefore, the smartest thing to do is to escape and get to a well-lit public area. In jujitsu, you are taught a way to escape from such grips and get away.

Second, if the only fighting you know how to do involves hurting somebody quickly and terribly, you might get in giant difficulty. In bar fights, or if a mugger attacks you, if you seriously injure them or kill them, you may pretty much certainly face a lawsuit. Having the ability to escape, immobilize, or subdue an opponent without causing them significant harm neatly avoids this problem. Martial art is a great form of keeping fit and self defence...

Obviously, both issues have to be dealt with. Jujitsu, by teaching a way to immobilize an opponent with holds, joint-locks, and pins, allow you to do both. You can pin Cousin Eddie until he calms down whilst causing him tiny, if any, harm. On the other hand, if you want to, you can disarm the mugger and throw them to the ground dazed.