Judo is a fun and simple game that is based on the deadly war art of Jujitsu, but with the deadly stuff removed and made safe to play. I know there are several dozen different styles of Jujitsu. I am not familiar with the two styles you mention, but I do have a 2nd degree black belt in a different style of Judo & Jujitsu. Jujitsu is a war art that was developed for unarmed and unarmoured people to fight armed and armoured soldiers, mostly by fracture dislocating limbs. In Judo, the throws and holds all stop before damage is done. The throws are guided so the person being thrown does not land on their head, breaking their neck ... In Jujitsu, the same throw is not guided gently, but rather is aimed so the person does break their neck ... Judo joint locks are held at the point where there is pain, but do not continue through with a break to the limb ... In Jujitsu, you do not stop or pause, you go right on through and break the limb. Knowing Judo is a significant amount of knowing Jujitsu, the difference is just following the rules of the friendly game and breaking the rules when there is real combat. The game of TaeKwonDo is very similar ... TKD is the game developed from a mix of Hapkido, Hwrangdo, and TangSooDo ... the other three are the deadly war arts while TKD is a friendly game of tag played for points ... TKD, like Judo, is based on the war arts, but has rules to keep the players safe from harm ... in real combat, the rules are discarded and your attacker is intentionally harmed. All I know of Capoeira is that it is was developed by mostly black slaves and disguised as an acrobatic dance so that slave masters would not recognize it as practicing for combat. It is highly deceptive. Compared to the above mentioned arts, Tai Chi Chuan and Tanaka-Ryu Ninjitsu are far more complete ... they include much more lesson sets in deep meditation, internal control, anatomy, physiology, herbal medicines, accupressure points, poisons and antidotes, and even more various weapons than even the diverse Hapkido.