This paper focuses on flexible teamwork in dynamic and real-world multi-agent domains. Such teamwork is not simply a union of agents’ simultaneous execution of individual plans,even if such execution pre-coordinated. Indeed, uncertain-ties in complex, dynamic domains often obstruct pre-plannedcoordination, with a resultant breakdown in teamwork. Thecentral hypothesis in this paper is that for durable teamwork,agents should be provided explicit team plans, which directlyexpress a team’s joint activities. When agents execute such team plans, they abide by certain "commonsense" conventions of teamwork. Essentially, such conventions providea deeper model of teamwork, facilitating flexible reasoningabout coordination activities. Such a framework also frees the planner or the knowledge engineer from specifying very detailed low-level coordination plans. This framework has been implemented in the context of a real-world synthetic environment for helicopter-combat simulation.