To explain the distribution of civil wars, guerrilla warfare, and revolutionary outbreaks, the literature on modern political violence has shifted, broadly speaking, from a modernization perspective that emphasized the role of material conflict and of grievances to a more recent research program that stresses the geographical and organizational opportunities that insurgents may have to engage in violence. Drawing on those lines of inquiry equally, this article offers an integrated analytical model that considers both the motives and the opportunities of states and rebels. Civil wars, guerrillas, and revolutionary outbreaks are seen as a result of the nature and distribution of wealth in each country. Systematic and organized violent conflicts are most likely in economies where inequality is high and wealth is mostly immobile, that is, in societies where those worse off would benefit substantially from expropriating all assets. Violence is conditional on the mobilizational and organizational capacity of challengers and on the state capacity to control its territory. The theory is tested on data on civil wars from 1850 to 1999 for the whole world and on data on guerrilla warfare and revolutionary episodes spanning the years from 1919 to 1997 across all countries.