Judo is a modern martial art and combat sport . Its most prominent feature is its competitive element, where the object is to either throw or take down one's opponent to the ground, immobilize or otherwise subdue one's opponent with a grappling manoeuvre or force an opponent to submit by joint locking or by executing a strangle hold or choke.

Strikes and thrusts by hands and feet as well as weapons defences are a part of judo, but only in pre-arranged forms (kata) and are not allowed in judo competition or free practice (randori).

Equipments:

The mat

Judo takes places on vinyl-covered foam mats called tatami covering an area of 14m square. This area is split into three specific areas, the inner contest area which is bounded by a one-metre red area, which alerts judoka that they are nearly out of bounds and finally the outside zone, which is three metres wide. That area is classed out of bounds.

Two pieces of tape, one blue and one white, appear on the middle of the contest area. These are four metres apart and mark where the opponents stand to begin and end a bout.

Uniforms

Loose fitting uniforms called judogi are worn for the contest. These consist of pants, a jacket and a belt tied at the waist. All competitors will wear a black belt to signify their dan grades.

Rules of judo

Bouts: A judo bout is a match between two opponents, or judoka, trying to score either by throwing the opponent or by applying a legitimate hold that makes the opponent submit or immobilises him or her for a specified time. The first judoka to score one point wins the contest.

Bouts last five minutes for both men and women. If neither person has scored a point by the end the winner is the contestant who scores half a point. If both or neither scores half a point, the winner is determined by who has accumulated the most credits, counted in koka and yuko.

Although neither results in actual points, a yuko is awarded if two elements of a throw are missing or a judoka pins an opponent for 15 to 19 seconds. A koka is awarded if three elements of a throw are missing or if the opponent is pinned for 10 to 14 seconds.

Scoring

One point can be scored and therefore the bout won by pulling off a good throw. Immobilising an opponent with a legal move for 25 seconds or forcing them to submit during a move such as an arm lock can also end the contest.

Winning by a point in judo is called an ippon. To achieve an ippon with a throw, it must meet four criteria. The opponent must be thrown mainly onto his or her back, and the throw must be made with control, force and speed.

It is also possible to accumulate moves of a half point value to achieve the necessary point. A half point is called a waza-ari, and is awarded when a judoka almost scores an ippon. When it is awarded after a throw it means three of the four criteria were met, or if awarded following a hold it means it was only held for 20 seconds.

Penalties

Penalties can lead to the credits and points being awarded. The smallest offences lead to koka, the more significant to yuko. More serious offences may result in hansoku-make, which means an ippon is awarded against the transgressor, but the referee must confer with the judges before awarding such a penalty.

Other rules

•  At the beginning and end of each bout, the two judoka must bow to each other and the contest area.
•  Judoka must be clean and have dry skin and short nails on both feet and hands. They also must be free from body odour!
•  A judoka in a hold submits by tapping twice on the mat with a hand or foot. Punching or putting a hand, foot, leg or arm on an opponent's face is prohibited.
•  Judoka is not permitted to bend back an opponent's fingers to break a hold. If an injury serious enough to end the bout occurs, and an opponent is clearly to blame from an illegal move, they will lose the bout
•  Judoka may not make derogatory remarks or gestures to their opponents.

Governing body:

International Judo Federation (IJF)

Major Championships:

Olympics

Commonwealth Games

World Judo Championships