This article reviews the literature on civil war. We focus on the most recent period of scholarly activity, beginning in the early 2000s when the publication of prominent quantitative studies triggered a surge in the empirical research of civil war as a well-defined conceptual category. We identify three explanatory logics that have dominated much of this literature and that view civil wars as a consequence of greed, grievances, and opportunities, respectively. We evaluate the arguments and findings of these theoretical approaches with respect to each of the main phases of war: outbreak, wartime dynamics, conflict termination, and postwar recovery. The article concludes by identifying key challenges confronting future civil war research. In particular, we emphasize the continuing need to advance theories that bridge the main explanatory logics as well as the different phases of conflict. Researchers should also pay more attention to defining the appropriate spatiotemporal scope of their studies.