Forms (kata) are pre-arranged patterns of attack and defence, which in judo are practised with a partner for the purpose of perfecting judo techniques. More specifically, their purposes include illustrating the basic principles of judo, demonstrating the correct execution of a technique, teaching the philosophical tenets upon which judo is based, allowing for the practice of techniques that are not allowed in competition, and to preserve ancient techniques that are historically important but are no longer used in contemporary judo.
Knowledge of various kata is a requirement for the attainment of a higher rank.
There are seven kata that are recognised by the Kodokan today:
- Free practice forms (Randori no Kata), comprising two kata:
- Throwing forms (Nage no Kata)
- Grappling forms (Katame no Kata)
- Old style self-defence forms (Kime no Kata)
- Modern self-defence forms (Kodokan Goshin Jutsu)
- Forms of "gentleness" (Ju no Kata)
- The five forms (Itsutsu no Kata)
- Ancient forms (Koshiki no Kata)
- Maximum-efficiency national physical education kata (Seiryoku Zen'yō Kokumin Taiiku no Kata)
There are also other kata that are not officially recognised by the Kodokan but that continue to be practised. The most prominent example of these is the Go no sen no kata, a kata that focuses on counter-attacks to attempted throws.