Abstract. Agent-based systems that are composed of simple locally interacting agents but which demonstrate complex group behavior o er several advantages over traditional multi-agent systems. A well-designed complex agent-based systems is an e cient, robust, adaptive and stable system. It has very low communication and computational requirements, meaning that there are virtually no constraints on the system size. The simplicity of agent interactions also makes it amenable to quantitative mathematical analysis. In addition to o ering predictive power, mathematical analysis enables the system designer to optimize system performance. To date, there have been relatively few implementations of complex agent-based systems, mainly because of the di culty of determining what simple agent strategies will lead to desirable collective behavior in a large system. We claim that there exists a set of primitive agent strategies, similar to the basis behaviors in behavior-based robotics, from which co...