The only organized rules in Judo deal with tournament fighting, also known as Shai. During these competitions players fight each other to win points that will allow them to beat their opponent. Players fight in a designated area that is prepared for combat. Color coded areas designate where players can fight. The picture below is of a competition tournament area. Points are awarded for throws and pins. The number of points is proportional to the strength of the throw or the length of the pin.

An automatic win can be accomplised by a very strong and clean throw, pinning for 25 seconds, or making your opponent submit via choke or armlock. As fighting is dangerous, especially with the ability to choke or armlock a person, there are specific rules in place to keep players safe. There is an exhaustive list of regulations that pertain to all aspects of tournament competition, the link below will direct to the official site.

Overview:

Competition Area - specific measurements of safe and unsafe areas.

Uniforms - cleanliness, fit, color, and condition.

Competition - techniques, time limits, sportsmanship, and scoring.

IJF Rules: