An integrated multi-agent robot system (NTU-Formosa) for robot soccer games was built in this study. The system consists of multiple mobile robots, a vision system, a wireless communication system, and a host computer. The multiple robots can be cooperatively controlled as they play a robot soccer game in an unknown and dynamic environment. The development of the system involved mechanism design and manufacture, integration of the electromechanical system, vision servoing, pattern recognition, decision-making, wireless communication, motion control, and centralized coordination control. The developed system has satisfactory performance in terms of compactness, stability, robustness, and mobility. To better understand the behaviors of the ball and robots in a robot soccer game, the free motion dynamics of the robots and ball and the collision dynamics among them were derived and analyzed in this study. To coordinate the multiple robots well, a flexible strategy-based decision-making system is proposed to perform centralized control. An experiment was conducted to examine the performance of NTU-Formosa, and the results obtained are satisfactory.