As with all sports the rules of the game are exhaustive and dull to say the least. But to summarize the game goes something like this: a bout lasts 3 minutes and has 2 halves.

The 2 players are distinguished by a red belt and a white belt and are called "tanto" and "toshu". The red player has a tanto (Rubber knife) and plays the role of attacker. He tries to hit his opponent on the target area - torso above the belt and below the armpits. He will attempt to resist his opponent's techniques.

The white player is unarmed and must avoid the strikes of his opponent, take control of him and either throw him or pin him using a recognisable technique from the randori no kata. At the end of 1m30 the tanto is exchanged.

The scoring is very similar to that of Judo.

• A perfect throw or pin scores ippon (4 points)
• A recognisable technique scores a waza ari (2 points)
• A balance break scores a yuko (1 point).
• A clear strike to the target area from correct distance and in good posture by "tanto" scores a tsuki ari (1 point).

At the end of the bout scores are totalled and the highest score wins.