Kata (型) are detailed patterns of defense-and-attack movements used by many traditional martial arts such as Budo disciplines (Aikido, Iaido, Jodo, Judo, Jiu_jitsu, Karate, Kendo) and Tae Kwon Do. Tai Chi Chuan practice also resembles the kata of other martial arts.
The word kata means "form". The form can be composed for solo practise, like in karate, or for exercise in pairs.
According to legend, the kata in Karate were devised by a Japanese master, banished to a small island for his drunkenness. With no one to practice with, he instead put together sequences of moves performed solo. Karate students rowing to the island were then taught the kata in return for smuggled alcohol.
The kata practitioner executes a specified series of from 20 or so to as many as 70 moves, generally with stepping and turning, and attempting to maintain as nearly-perfect form as possible. The number of moves in a kata may be referred to in the name of the kata eg. Gojushiho, which means 54 steps. The number of moves may also have links with Buddhist spirituality - the number 108 is significant in Buddhism and kata whose numbers of moves are factors of 108 such as 54, 36 and 27 reflect this link.
The practioner is generally counselled to visualize the enemy attacks, and his or her responses, as actually occurring.
In teaching the open handed kata, most systems start with a series of five basic kata named Pinan in some systems and Heian in others. By working through this series (in order: Shodan, Nidan, Sandan, Yodan, Godan) the practitioner learns all the basic stances and techniques before moving on to more advanced kata.
Many martial arts use kata for public demonstrations and in competitions, awarding points for style, balance, timing, verisimilitude, etc.
Critics of kata argue that they produce stereotyped responses, making unexpected moves by opponents more dangerous.