In this paper we assess how perceptions of park legitimacy influence individual willingness to self-restrict their resource use - an important issue when designing conservation approaches like community ecosystem payments where the existing institutional context influences the willingness to collaborate in nature conservation. To assess the willingness to self-restrict resource use we conducted a field experiment in two Costa Rican villages bordering a protected area. We framed the experiment to assess the impact of legitimacy perceptions: With framing we introduced the game as a protected area natural resource extraction game, while without framing the game was introduced using the usual, abstract wording. The results indicate that framing lowers extractions. The difference with non-framed extractions is not significant, however, until we control for individual legitimacy perceptions. From the perspective of ecosystem service payments our results indicate that perceptions of the current institutional context influence the extent to which participants cooperate and are willing to self-enforce their resource use. © 2013 Elsevier B.V.