Judo, (Japanese, way of softness or gentle way), a martial art derived from ju-jutsu and a form of highly sophisticated wrestling
A contest takes place on a mat 9 m (30 ft) square. Outside the mat there is a safety area of 1 m (3 ft 3 in) all round. The tatami (mats) are made of compressed straw with a canvas covering and measure 2 by 1 m (6 ft 6 in by 3 ft 3 in). The mats are pushed together and held in place by a wooden frame. Modern-day mats are composed of vinyl-covered foam. A contest is judged by a referee within the contest area, plus two judges situated at opposite corners of the mat. The contest must take place within the limits of the area.

At the start the fighters face each other at a distance of 4 m (13 ft) and make a standing bow. This is a traditional courtesy and formality before and after a bout. The referee then calls hajime (begin). A bout lasts a minimum of 3 minutes and a maximum of 20. There are no rounds, as in boxing, but a decisive score may end the contest. If a contest is not a clear victory one way or the other, the judges indicate the winner with their batons and the referee has the deciding vote.