Depending on the rules, full-contact fighting may allow participants to use full force to disable or knock out an opponent or achieve submission. At its extreme, the term “full contact” may mean that all techniques of attack are permitted and that no zones of the body are forbidden from attack. In the early UFC events, judges, time limits, and points were not used. The outcome of a competition was determined by the inability of one of the participants to continue. In Portuguese, vale tudo, which means “anything goes,” is a form of full-contact fighting. Full-contact rules are used in almost all mixed martial arts competitions held by the UFC, PRIDE, Pancrase, and Shooto. Recently, however, safety rules were written and the use of protective gloves was added. Brazilian Jiu-Jitsu and judo, which do not allow striking, are still full-contact fighting in that full force can be used during grappling and submissions. Sambo has full-contact variations of its fighting system.

Some practitioners of full-contact, hand-to-hand combat believe that physically defeating the enemy is the only goal in a competition. Winning a sports match by rules does not appeal to them. They treat competition in the martial arts as a matter of life and death, and they pursue training and the study of fighting techniques without regard to competitive rules or ethical and legal concerns. Even so, with precautions such as a referee and a ring doctor, full-contact matches with basic rules can serve as a useful gauge of a practitioner’s overall fighting ability and encompass striking, grappling, holds, and other broad categories.