Scholars have tended to recommend 'optimal' solutions for coping with open-access problems related to common-pool resources such as fisheries, forests and water systems. Examples exist of both successful and unsuccessful efforts to rely on private property, government property and community property. After briefly reviewing how the often-recommended solutions have worked in the field, I suggest that institutional theorists move from touting simple, optimal solutions to analysing adaptive, multi-level governance as related to complex, evolving resource systems.