The exact meaning of randori depends on the martial art it is used in. In Judo and Tomiki Aikido, it most often refers to one-on-one sparring where partners attempt to resist and counter each other's techniques. In other styles of Aikido, in particular Aikikai, it refers to a form of practice in which a designated aikidoka defends against multiple attackers in quick succession without knowing how they will attack or in what order. This for of randori is not sparring, and the attackers are not allowed to resist or attempt to counter the defender's techniques.