Sanction opportunities are often introduced to promote cooperative choice behavior. Experimental studies have repeatedly demonstrated that the use of both rewards and punishments can indeed effectively increase cooperation. However, research has only recently begun to identify the determinants of the willingness to sanction. We investigate the use of costly sanctions to promote cooperation in the context of social dilemmas. We argue and demonstrate that people’s willingness to costly reward and punish is not only determined by the type of sanction (reward versus punishment) but is also moderated by the type of social dilemma people face (public good dilemma versus common resource dilemma). In two experiments, we demonstrate that people reward more and to a greater extent than they punish, especially in a public good dilemma compared to a common resource dilemma.