Authoritarian successor parties, or parties that emerge from authoritarian regimes but that operate after a transition to democracy, have become prominent actors in Africa, Asia, Europe, and Latin America since the third wave. What explains their prevalence? What are their effects on democracy? This article argues that such parties often benefit from authoritarian inheritance: they may inherit valuable resources from former dictatorships that, paradoxically, help them to thrive under democracy. Despite their undemocratic origins, the article argues that their effects on democracy are not entirely negative, but double-edged.