This chapter introduces the phenomenon of party violence, discusses the scope conditions and central arguments of the book, and offers a methodological justification for the distinct cross-regional comparison of Kenya and India. It also details the multiple data sources used to develop the book’s main claims as well as the subnational research sites investigated in both countries. Substantively, the chapter holds that party instability is an underappreciated factor in the broader instrumentalist literature on elites’ decision-making about conflict. It argues that instability matters because it can make the deployment of violence less costly and risky for politicians and thereby incentivize the production of recurring and severe conflict.