The object in a judo match is to either throw the opponent to the ground on his back, to pin him to the ground on his back, or to force him to submit using a choke or an armlock. Any of these score ippon (一本), immediately winning the match. When throwing, anything besides landing the opponent full on his back, such as landing on the hip or shoulder, will score waza-ari (技有), yuko (有効) or koka (効果) (waza-ari being the highest of the 3, koka the lowest), or no score. A waza-ari is a "near-fall", two of which will earn the match.
Yuko and koka are scores of lesser value that are not cumulative to either that higher waza-ari. Rather, they are used as deciders if the match ends before either of the higher scores is achieved. On the typical electronic scoreboard, yuko scores 010 and koka scores 001.
In the event that the match a draw, the clock is reset to match-time, and the contest is resolved by the Golden Score rule. This is a sudden death situation wherein the first contestant to achieve any score wins. If there is no score during this period, then the decision is by a majority opinion of the referee and the two corner judges.
After a non-ippon throw occurs (whether or not it is scored), combat may continue on the ground. Pinning an opponent (holding both shoulders to the mat) for 25 seconds results in ippon. Holding the pin for 20 seconds scores waza-ari; if waza-ari was previously scored, this constitutes ippon, since two half-points will complete the ippon score. An automatic ippon is also granted when one's opponent submits, which frequently occurs when strangleholds / armlocks are used. If there is no ippon, the one with the highest score wins.
Penalties may be given for being inactive during the match or using illegal techniques and fighting must be stopped if a participant is outside the designated area on the mat (tatami). If the referee and judges need to discuss something during groundwork, the referee will call sonomama (which means "do not move") and both fighters must stop in the position they are in. When they are done, the referee says yoshi and the match continues.
All scores and penalties are given by the referee. The judges can make a decision to change the score or penalty given by the referee.
In competition: The literal meaning of judo is "the gentle way", but competition judo, one of the roughest and most demanding of sports, could hardly be called gentle. Regulation time in a World Championship or Olympic match is only 5 minutes, but will leave participants exhausted; in the event of a tie, matches proceed to an overtime phase called Golden Score which can last as long as regulation time.
Because competition judo does not contain the kicking and punching so common to other martial arts, Judo is often portrayed as friendlier than, for instance, Karate (although some forms of Karate emphasize the control of character and aggression). Proponents believe this contributes to judo being underrated as a method of self-defence although advanced kata do contain defences against kicking, punching, and armed techniques. In addition, while throws executed with proper break falls on soft mats can seem light and graceful, their more practical application on a hard surface (and potentially with greater intent to harm) could be dangerous. Even in the controlled environments of a match or dojo training session, injuries can easily occur due to a lapse in focus or overzealous application of a technique.
Mixed martial arts: Using their knowledge in ne-waza/grappling and tachi-waza/standing-grappling, various accomplished judo practitioners have also competed in mixed martial arts matches. Fedor Emelianenko, PRIDE Fighting Championships's current heavyweight champion and consistently ranked the world's best heavyweight mixed martial arts fighter, has a background in judo and sambo.
Karo Parisyan is a top contender for the UFC's welterweight championship, and Rameau Thierry Sokoudjou and Hidehiko Yoshida, an Olympic gold medalist in 1992 and World Judo Champion in 1999, are also top fighters in PRIDE FC. Other Olympic gold medalist and world champion judokas such as Pawel Nastula and Yoon Dong Sik also fight in PRIDE.
It should be noted that the ability to throw an opponent to his back and apply a pinning technique is of enormous importance in these kinds of competitions, as is the ability to finish off a downed opponent with strikes or a submission hold. Judo, uniquely among combat sports, puts equal emphasis on the initial throwing and the final pinning and submitting phases of combat, ideally enabling practitioners to dominate grappling-fights from the get-go.
