Traditional AI research has not given due attention to the important role that physical bodies play for agents as their interactions produce complex emergent behaviors to achieve goals in the dynamic real world. The RoboCup Physical Agent Challenge provides a good test bed for studying how physical bodies play a significant role in realizing intelligent behaviors using the RoboCup framework (Kitano et al., 1995). In order for the robots to play a soccer game reasonably well, a wide range of technologies needs to be integrated, and a number of technical breakthroughs must be made. In this article, we present three challenging tasks as the RoboCup Physical Agent Challenge Phase I: (1) moving the ball to the specified area (shooting, passing, and dribbling) with no, with stationary, or with moving obstacles; (2) catching the ball from an opponent or a teammate (receiving, goal keeping, and intercepting); and (3) passing the ball between two players. The first two tasks are concerned with single-agent skills, while the third is related to a simple cooperative behavior. Motivation for these challenges and evaluation methodology is given.