State repression includes harassment, surveillance/spying, bans, arrests, torture, and mass killing by government agents and/or affiliates within their territorial jurisdiction. Over the past 40 years, the systematic study of state repression has grown considerably. The development of this work, however, has been uneven. Though unified in their focus on the problem of order (i.e., trying to ascertain how political authorities wield coercive power amid potential and actual domestic challengers), different scholars tend to emphasize distinct aspects of the topic. Consequently, a great deal of progress has been made in specific areas but others have lagged behind. In this review, I attempt to identify the dominant traditions in the repression literature, the core empirical findings, and some persisting puzzles.