Techniques

While Judo includes a variety of rolls, falls, throws, pins, chokes, jointlocks, and methods of percussion, the primary focus is on throwing (nage-waza), and groundwork (ne-waza). Nage-waza is divided in two groups of techniques, standing techniques (tachi-waza) and sacrifice techniques (sutemi-waza). Standing techniques are divided in hand techniques (te-waza), hip techniques (koshi-waza) and foot/leg techniques (ashi-waza). Sacrifice techniques are divided into those in which the thrower falls directly backwards (ma-sutemi-waza) and those in which he falls onto his side (yoko-sutemi-waza).

The groundwork techniques are divided into: attacks against the joints (kansetsu-waza) known in English-speaking countries as "leg-" and "arm-locks", stranglehold (shime-waza), and holding or pinning techniques (osaekomi-waza).

A kind of sparring is practiced in judo, known as randori, meaning "free practice". In randori, players (known as judoka) may attack each other with any judo throw or grappling technique. Striking techniques (called atemi-waza) such as kicking and punching, along with knife and sword techniques are retained in the katas taught to higher ranking judoka (for instance, in the kime-no-kata), but are forbidden in contest (and usually prohibited in randori), for reasons of safety. Also for reasons of safety, chokeholds, jointlocking - and the sacrifice (sutemi) techniques, which can be very spectacular, are often subject to age and/or rank restrictions; in the United States, one must be 13 or older to use chokeholds, and 17 or older, or hold the rank of Shodan (first grade black belt) or higher to use arm bars.

In randori and shiai (tournament) practice, when an opponent successfully executes a chokehold or joint lock, one "taps out" by tapping the mat or one's opponent at least twice in a manner that clearly indicates the submission. When this occurs, the match is over, and the tapping player has lost, but the chokehold or joint lock ceases. Because this allows a merciful exit to the match, injuries related to these holds are quite rare.