RoboCup is a much larger event than just the Aibo robotic dog competition. This year (2001) will be the fifth annual RoboCup competition. This is the first year that it will be held in the United States. There are five different leagues that compete at robot soccer. These are:

Soccer Simulation
Small-Size Soccer Robots
Medium-Size Soccer Robots
Soccer Legged Robots (the Aibo dogs)
Humanoid Robot Soccer
In addition to these five leagues, there is also a Junior RoboCup league, and several Rescue Robot competitions.

Soccer Simulation
Simulated robotic soccer is played by two teams using the Soccer Server. Each team writes a computer program that directs a team of individual simulated robots. An interesting feature of the Soccer Server is that each robot on the team has different strengths and weaknesses, and the agents get "tired" during the course of play.

Small-Size Soccer Robots
Small-size robots are not permitted to cover more than 180 square centimeters of floor area and must fit inside a 18 cm diameter cylinder. Robots must be colored black, and a height restriction is placed on teams using a global vision system. Teams consist of no less than 1 and no more than 5 robots. Each team may designate no more than one robot to serve as the goal keeper.

Medium-Size Soccer Robots
Medium-sized soccer robots are approximately 50x50x80 cm. The rules for medium-sized robotic soccer differs from small-size robotic soccer in that global vision is not permitted. Robots are, however, allowed to have on-board vision and wireless communication between robots. The robots are fully autonomous and no human intervention is permitted.

Sony Legged Robot League
Sony Aibo robotic dogs are used for the legged robot competition. Teams consist of three robots. The challenges of Aibo soccer are that the dogs have very limited vision and processing power. No hardware modification of the robots is permitted.

Humanoid Soccer Robot League
This is the first year that humaniod robots will compete in robotic soccer. As the event is still new, the rules are under discussion and have not yet been finalized.

RoboCup 2001 will take place in Seattle, Washington on August 2-10. For more information about RoboCup, please see the official web site: http://www.cs.cmu.edu/~robocup2001/