Kids Web Japan

Competition in Judo

The Kodokan judo rules that were used in past Olympic Games are still in use in Japan, but in this article, we'll refer to the International Judo Federation rules (as of March 2021) that are currently used for international competitions including the Olympics.

Judo Mats and Referees

Judo matches are fought between two people on a square mat measuring 8–10 meters (26–33 feet) per side. There is one head referee and two assistant referees. Outside the mat, there is also a scoring official, a timing official, a recording official, and a judging referee. Match time is four minutes. Any one of 68 nage-waza (throwing techniques) and 32 katame-waza (grappling techniques) may be used to win.

A schematic diagram of the mat

Getting Points — Ippon and Wazaari

Scores are awarded in various ways, with the highest being an ippon, when a competitor throws the opponent so that the opponent’s back completely touches the mat. A competitor can also win using katame-waza: by grappling the opponent and forcing the opponent to say "Maitta (I give up)," or getting the opponent to tap their body or the mat twice, the competitor can win the match instantly. A competitor can also gain points for skillful attacks called wazaari, even if they do not lead to an ippon. Two wazaari count as an ippon, ending the contest.

Holding the opponent down against the mat also results in an ippon after 20 seconds or when the opponent submits. It counts as a wazaari after 10 or more seconds.

Rule Breaking and Overtime

Points are awarded not only for good moves but also penalties committed by the opponent, such as stalling, moving out of the mat, or refusing to attack. Illegal or dangerous techniques, moreover, can lead to disqualification. Shido (warnings) are given for minor penalties. Three shido can lead to disqualification. If matches end in ties, they go into overtime under the Golden Scoring method. Overtime matches end with either wazaari, ippon, or disqualification.

A judo match (Kodokan Judo Institute)


One of the appeals of judo is the emphasis on etiquette (reihou), which shows that competitors respect their opponents. Competitors bow by bending their upper bodies forward at an angle of about 30 degrees. Competitors face forward and then bow facing each other from their start lines, before and after each match. Some competitors also bow when they enter and leave the mat.