There are four scores in judo. An ippon (一本) (one point) is a winning score. A waza-ari (技あり) (half point) is near ippon. If the contestant is awarded two ippons, they will win by waza-ari-awasete-ippon (技あり合わせて一本) (two waza-ari make an ippon).
Yuko (有効) (effective), and koka (効果) (minor score) are different from waza-ari in that no amount of yuko or koka will be equivelent to the next higer score. A yuko is better than a koka. One waza-ari is better than any yuko and one yuko is better than any koka.
If the match is not decided by an ippon, then it will be decided based on who has better scores. If the score is completely even, then the contestants will fight again, or the judge declares a draw. If the contestants fight again, then the winner is the first person that scores. This is called the golden score.
The main judge declares who gets what points. The corner judges will signal if they disagree with the main judge which the main judge will take in to consideration. To make it easier to see, the judges uses hand signals.
||Two Waza-ari make an Ippon
The Referee shall announce Ippon when in his opinion the applied technique corresponds to the following criteria:
- When a contestant with control throws the other contestant largely on his back with considerable force and speed.
- When a contestant holds with Osaekomi-waza the other contestant, who is unable to get away for 25 seconds after the announcement of Osaekomi.
- When a contestant gives up by tapping twice or more with his hand or foot or says Maitta (I give up!) generally as a result of Osaekomi-waza, Shime-waza or Kansetsu-waza.
- When a contestant is incapacitated by the effect of a Shime-waza or Kansetsu-waza.
Equivalence: Should one contestant be penalised with Hansoku-make, the other contestant shall immediately be declared the winner
Gesture for Waza-ari-awasete-ippon
Should one contestant gain a second Waza-ari in the contest, the Referee shall announce Waza-ari-awasete-ippon.
The Referee shall announce Sōgō-gachi in the following cases:
- Where one contestant has gained a Waza-ari and his opponent subsequently receives three (3) Shidos.
- Where one contestant, whose opponent has already received three (3) Shidos, is subsequently awarded a Waza-ari.
In the case where both contestants score Ippon or Sōgō-gachi simultaneously the contest shall be decided by the “Golden Score” contest.
The Referee shall announce Waza-ari when in his opinion the applied technique corresponds to the following criteria:
- When a contestant with control throws the other contestant, but the technique is partially lacking in one (1) of the other three (3) elements necessary for Ippon (see Article 20 (a) and Appendix).
- When a contestant holds with Osaekomi-waza the other contestant who is unable to get away for 20 seconds or more, but less than 25 seconds.
Equivalence: Should one contestant have been penalised three (3) Shidos, the other contestant shall receive Waza-ari immediately.
The Referee shall announce Yuko when in his opinion the applied technique corresponds to the following criteria:
- When a contestant with control throws the other contestant, but the technique is partially lacking in two (2) of the other three (3) elements necessary for Ippon.
- Partially lacking in the element of "largely on the back" and is also partially lacking in one of the other two (2) elements of "speed" or "force".
- Largely on the back but partially lacking in both of the other two (2) elements of "speed" and "force".
- When a contestant holds with Osaekomi-waza the other contestant who is unable to get away for 15 seconds or more but less than 20 seconds.
Equivalence: Should one contestant have been penalised two (2) Shidos, the other contestant shall receive Yuko immediately.
Regardless of how many Yukos are announced, no amount will be considered equal to a Waza-ari. The total number announced will be recorded.
The Referee shall announce Koka when in his opinion the applied technique corresponds to the following criteria:
- When a contestant with control throws the other contestant onto one shoulder, his thigh(s), or buttocks with speed and force.
- When a contestant holds with Osaekomi-waza the other contestant who is unable to get away for 10 seconds or more but less than 15 seconds.
Equivalence: Should one contestant have been penalised one (1) Shido, the other contestant shall receive Koka immediately.
Regardless of how many Kokas are announced, no amount will be considered being equal to a Yuko or a Waza-ari. The total number announced will be recorded.
Throwing an opponent on the front of his body, knee(s), hand(s), or elbow(s) will only be counted as the same as any other attack. Similarly an Osaekomi of up to nine (9) seconds will be counted as an attack.
Penalties are important in competition in order to keep all competitors safe and in the spirit of judo. There are also penalties to keep players from being too passive or overly defensive. As long as the contestant plays good, safe judo, and does not stall, they shouldn't get any penalties.
There are four penalties given in judo (from least to most severe): shido (指導), chui (注意), keikoku (警告), and hansoku-make (反則負け). However, starting in 2003, International Judo Federation simplified the rules to use only shido and hansoku-make. Once a contestant recieves hansoku-make, the contestant is disqualified and excluded from the tournament.
 International Rules vs. Japan Rules
The original way of scoring penalties was by using four types of penalties. Each penalty gave the equivalent point for the opponent. The penalties are shido (eq. koka), chui (eq. yuko), keikoku (eq. waza-ari), and hansoku-make (eq. ippon). In this system, the contestant can only get the penalty once. If the contestant receives two of the same penalty, the second penalty will be the next highest penalty. For example, if the player receives two shidos, the first will be a shido and the second will be a chui.
The International Judo Federation decided to change the rules to make them easier to understand. The new international rules has simplified the amount of penalties from four to only two, shido and hansoku-make. A hansoku-make is equivalent to the old keikoku and hansoku-make. A shido is equivalent to the old shido and chui. The first shido serves as a warning, the second gives a yuko, the third a waza-ari, and finally the 4th shido is announced as hansoku-make and gives the opponent an ippon.
||Defeat by Decision
 Passive or Preventive Action
- To intentionally avoid taking Kumikata in order to prevent action in the contest.
- To adopt in a standing position, after Kumikata, an excessively defensive posture. (Generally more than 5 seconds).
- To make an action designed to give the impression of an attack but which clearly shows that there was no intent to throw the opponent. (False attack).
- To stand, both feet completely within the danger zone unless - beginning an attack, executing an attack, countering the opponent's attack or defending against the opponent's attack. (Generally more than 5 seconds)
- In a standing position, to continually hold the opponent's sleeve end(s) for a defensive purpose (Generally more than 5 seconds) or to grasp by "screwing up" the sleeve end(s).
- In a standing position, to continually keep the opponent's fingers of one or both hands interlocked, in order to prevent action in the contest. (Generally more than 5 seconds).
- In a standing position to take any grip other than a "normal" grip without attacking. (Generally more than 5 seconds).
- In a standing position, before or after Kumikata has been established, not to make any attacking moves. This is called non-combativity, which may be taken to exist when in general, for approximately 25 seconds; there have been no attacking actions on the part of one or both contestants. Non-combativity should not be awarded when there are no attacking actions, if the Referee considers that the contestant is genuinely looking for the opportunity to attack.
- To insert a finger or fingers inside the opponent's sleeve or bottom of his trousers.
- To hold the opponent's sleeve end(s) between the thumb and the fingers (“Pistol” grip).
- To hold the opponent’s sleeve end(s) by folding it over (“Pocket” grip).
- From a standing position, to take hold of the opponent's foot/feet, leg(s) or trouser leg(s) with the hand(s), unless simultaneously attempting a throwing technique.
- To encircle the end of the belt or jacket around any part of the opponent's body. The act of "encircling" means that the belt or jacket must completely encircle. Using the belt or jacket as an "anchor" for a grip (without encircling), e.g. to trap the opponent's arm, should not be penalised.
- To take the Judogi in the mouth. (either his own or his opponent’s Judogi).
- To put a hand, arm, foot or leg directly on the opponent's face. The face means the area within the line bordered by the forehead, the front of the ears and the jaw-line.
- To put a foot or a leg in the opponent's belt, collar or lapel.
- To apply Shime-waza using the bottom of the jacket or belt, or using only the fingers.
- To go outside the contest area or intentionally force the opponent to go outside the contest area either in standing position or in Newaza. (See Article 9 - "Exceptions").
- To apply leg scissors to the opponent's trunk (Dojime), neck or head. (Scissor with crossed feet, while stretching out the legs).
- To kick with the knee or foot, the hand or arm of the opponent, in order to make him release his grip, or to kick the opponent’s leg or ankle without applying any technique.
- To bend back the opponent's finger(s) in order to break his grip.
Keikoku (Serious Warning)
- To apply Kawazu-gake. (To throw the opponent by winding one leg around the opponent's leg, while facing more or less in the same direction as the opponent and falling backwards onto him). Even if the thrower twists/turns during the throwing action, this should still be considered “Kawazu-gake” and be penalised. Techniques such as Osoto-gari, Ouchi-gari, and Uchi-mata where the foot/leg is entwined with opponent’s leg will be permitted and should be scored.
- To apply Kansetsu-waza anywhere other than to the elbow joint.
- To lift off the Tatami the opponent who is lying on the Tatami and to drive him back onto the Tatami.
- To reap the opponents supporting leg from the inside when the opponent is applying a technique such as Harai-goshi etc.
- To make any action which may endanger or injure the opponent especially the opponent's neck or spinal vertebrae, or may be against the spirit of Judo.
- To fall directly to the Tatami while applying or attempting to apply techniques such as Ude-hishigi-waki-gatame. To attempt such throws as Harai-goshi, Uchi-mata, etc., with only one hand gripping the opponent's lapel from a position resembling Ude-hishigi-waki-gatame (in which the wrist of the opponent is trapped beneath the thrower's armpit) and deliberately falling, face down, onto the Tatami is likely to cause injury and will be penalised. No intent to throw an opponent cleanly onto his back is a dangerous action and will be treated in the same way as Ude-hishigi-waki-gatame.
Hansoku-make (Defeat by Decision)
- To "dive" head first, onto the Tatami by bending forward and downward while performing or attempting to perform techniques such as Uchimata, Harai-goshi, etc. or to fall directly backwards while performing or attempting to perform techniques such as Kata-guruma whether standing or kneeling.
- To intentionally fall backwards when the other contestant is clinging to his back and when either contestant has control of the other's movement.
- To wear a hard or metallic object (covered or not).
 Against the Spirit of Judo
- To intentionally disarrange his own Judogi or to untie or retie the belt or the trousers without the Referee's permission.
- To pull the opponent down in order to start Newaza. However, the contestants shall be able to change from the standing position to Newaza in the following cases but if the technique used is not continuous, the Referee shall order both contestants to resume the standing position:
- When a contestant, after obtaining some result by a throwing technique changes without interruption into Newaza and takes the offensive.
- When one of the contestants falls to the ground, following the unsuccessful application of a throwing technique the other may take advantage of his opponent's unbalanced position to take him to the ground.
- When one contestant obtains some considerable effect by applying a Shime-waza or Kansetsu-waza in the standing position and then changes without interruption to Newaza.
- When one contestant takes his opponent down into Newaza by the particularly skilful application of a movement which does not qualify as a throwing technique.
- In any other case where one contestant falls down or is about to fall down, not covered by the preceding sub-sections of this article, the other contestant may take advantage of his opponent's position to go into Newaza.
Keikoku (Serious Warning)
- To disregard the Referee's instructions.
- To make unnecessary calls, remarks or gestures derogatory to the opponent or Referee during the contest.
- To make any action which may be against the spirit of Judo.