Commons projects, such as community-based natural resource management, have widespread appeal, which has enabled them to shrug off a mixed performance in practice. This paper discusses how the theoretical assumptions of common pool resource (CPR) theory may have inadvertently contributed to the unfulfilled expectations of commons projects. The paper argues that the individual ‘rational resource user’, encapsulated in the CPR design principles, struggles to provide clear direction for meaningful consideration of local norms, values and interests in commons projects. The focus of CPR theory on efficiency and functionality results in a tendency in commons projects to overlook how local conditions are forged through relations at multiple scales. Commonly politically complex and changing relations are reduced to institutional design problems based on deriving the incentives and disincentives of ‘rational resource users. The corollary is that CPR theory oversimplifies the project context that it is seeking to change because it offers little or no direction to deal with the social embeddedness of resource use or implications of different stratifications.