This paper proposes a notion, the ?ambit? of an action, that allows the degree of distribution of an action in a multiagent system to be quantified without regard to its functionality. It demonstrates the use of that notion in the design, analysis and implementation of dynamically-reconfigurable multi-agent systems. It distinguishes between the extensional (or system) view and intensional (or agent-based) view of such a system and shows how, using the notion of ambit, the step-wise derivation paradigm of Formal Methods can be used to derive the latter from the former. In closing it addresses the manner in which these ideas inform studies in the ethics of systems of artificial agents.