Tatami (the Mat): The competition is held on a mat measuring 10x10m with a danger area of 1m and an outer safety area of 3-4m. In most competitions the mat is green with a red danger area. 
  
Judogi (the Judo uniform): Judogi is made out of heavy cotton to allow athletes to grab on to their opponents' collar, sleeve, chest, belt and trousers when practising the various techniques. For many years there were only white judogi. In the Sydney 2000 Paralympic Games, blue judogi were added to make the distinction between competitors easier.

Belts: Judo belts are used to identify the athletes' skills, technical proficiency and contribution to the sport. Rank is shown by a belt colour. There are two types of rank: kyu and dan. Dan grades are the highest and shown by a black belt. Coloured belts show kyu grades. Although the grades vary among countries, the most universally accepted system is the following: Kyu grades decrease from six to one, the latter being the highest ranking, whereas dan grades increase from one to 10, 10 being the highest ranking.

Rank	Belt Color
6th kyu	white
5th kyu	yellow
4th kyu	orange
3rd kyu	green
2nd kyu	blue
1st kyu	brown
1st-5th dan	black
6th-8th dan	black or red-and-white
9th-10th dan	black or red

All beginners wear white belts. Black belts are awarded to students who have developed a degree of proficiency in the various techniques of Judo, either by passing an exam or through competition. They have shown commitment to being a serious student of Judo. There is a general perception that a black belt holder is a Judo expert. The 1st degree of black belt (the 1st dan) in Judo actually signifies that the student is truly ready to begin learning Judo.