Abstract: This article argues that in development studies, power is one of the most important, but at the same time most badly theorized topics. In most of the literature a `property-notion¿ of power is used assuming that people or groups have more or less fixed interests and levels of power. In this article a force field approach towards power is proposed that conceives of power as `relational¿ and the result of the working of multiple, intertwined institutions. Examples from agrarian communities in Mexico and Peru are given to show how overlapping institutions and the resulting force fields determine local power relations. Special attention is paid to the methodological implications of such an approach for studies on natural resource management. Attention is paid to: following the flow of action, paying attention to ideas and reflective talk and the quantification of specific sets of data on natural resources.