Jiu-jitsu today has many different guises. The most familiar, through exposure in the UFC and other no holds barred competitions, is Brazilian Jiu jitsu. This however is quite far removed from the traditional roots of jiu-jitsu.
Traditionally Jiu-Jitsu’s place was on the battlefield as a last ditch attempt to stay alive when the warrior or samurai had lost or broken their weapon. Due to the opponent wearing full armor the most vulnerable points of attack were at the joints where armor was less dense (in order to aid articulation of the limbs). Thus the use of joint locking rather than striking developed.
In the height of battle the need for fast and effective techniques was a must and so jiu-jitsu developed along in this vein. As already stated jiu-jitsu exponents utilized formidable joint locks, as well as precision strikes to unprotected area’s and throwing. The emphasis however was on staying upright as going to the ground was an extremely dangerous move. Ground techniques were taught as a backup system incase a person was knocked down but as little amount of time as possible was spent in such a precarious position.
I must point out at this point in my little addition to this great forum, that I do not intend to belittle Brazilian Jiu-Jitsu or any other system that places emphasis on fighting at such a range. I am merely expressing the fact that they used ne waza (ground techniques) only as a support range. This still holds true in many styles of jiu-jitsu and for self-defense purposes on today’s street should still be considered as a backup range.
Another main aspect of jiu-jitsu was its integral link with weapons systems. Many of the movements of Jiu-Jitsu developed from the movements used when handling a weapon such as sword or spear and so weapon systems were, and still are a major part of many jiu-jitsu syllabuses. The use of weapons and the unarmed defence from a an assailant using a weapon are very much a part of jiu-jitsu and the neglect of these ranges and techniques is a major blow to the heritage and authenticity of jiu-jitsu.
Later in it’s development jiu-jitsu developed attacks to all areas of the body, obviously for when the opponent was not in armor. Different Ryu (schools/styles) placed greater or lesser emphasis on certain techniques but nearly all Ryu covered most fighting ranges. Jiu-jitsu for that reason is still considered one of the most formidable self-defense systems in existence and one of the most complete systems (given the right ryu).