Abstract. This paper aims at providing a rigorous definition of selforganization, one of the most desired properties for dynamic systems (e.g., peer-to-peer systems, sensor networks, cooperative robotics, or ad-hoc networks). We characterize different classes of self-organization through liveness and safety properties that both capture information regarding the system entropy. We illustrate these classes through study cases. The first ones are two representative P2P overlays (CAN and Pastry) and the others are specific implementations of Ω (the leader oracle) shot query abstractions for dynamic settings. Our study aims at understanding the limits and respective power of existing self-organized protocols and lays the basis of designing robust algorithm for dynamic systems.