This chapter describes case selection, which is a crucial component of designing social research. Its importance can hardly be overstated because the cases you choose affect the answers you get. However, how should researchers select their cases? A careful inspection of the research question, the study’s objective, should be the starting point. The research question typically anchors the study in a research area, specifies the universe of cases, and guides its engagement with theory. Ideally, case selection is solely driven by methodology; however, practicality and feasibility considerations frequently make adjustments to the design necessary. Such considerations concern, for instance, the costs of data collection. The chapter introduces a few commonly used case selection strategies as well as two hotly debated topics in the literature on case selection: selecting on the dependent variable and random case selection.