On the ground, all coups share similar features. A group of military officers, or other elites, attempt to capture key strategy points and arrest the incumbent leader. Yet, the motivation behind a coup can differ significantly. Using a series of formal models, we identify three sets of circumstances that lead to coup attempts. First, when there is mass discontent with the regime and the elites fear losing their privileged position, they act to preempt a revolution. Second, when a leader underprovides for her supporters, the coalition of backers depose her and replace her in expectation of being better rewarded by her successor. Third, and perhaps most counterintuitively, coups are precipitated by leaders who overprovide rewards for their supporters. A global game model of institutional changes identifies such overprovision of rewards as a precursor to leader led attempts to purge and contract the coalition. Current elites use coups to preempt being purged. Using corruption as a measure of coalition rewards, the empirical analyses find that coups are most likely when 1) there is a heighten and growing level of mass protest; 2) leaders are under-providing their supporters with rewards; and, 3) when leaders provide more rewards than anticipated given economic and political conditions. The latter conditions also coincide with circumstances where purges and contractions in the winning coalition are likely.