Judo competitions during the Tokyo Games will take place at Nippon Budokan. Built in 1964, the arena can accommodate nearly 14,500 spectators. The arena will also host karate events at the Olympics.
Judo matches take place on rectangular mats, known as tatamis. Tatamis are usually made of pressed foam, although traditionally they were made of straw and came in many different sizes, depending on the region of Japan in which they originated. The tatamis are covered with a plastic material to provide good footing and are placed side by side on the competition platform to form a continuous surface.
There are two zones within the field of play: the contest area and the safety area. The contest area, which is where the combat takes place, is yellow and must be 10 meters by 10 meters (33 feet by 33 feet). The contest area is surrounded by the safety area, which is red and must be at least 4 meters (13 feet) on each side. During competition, an athlete can be thrown into the safety area as long as the throw begins in the contest area.