In Chapter 8, we examine how scale affects contestation, defined as the degree of electoral competition in a political community. We begin by offering a theoretical account of the impact of scale on contestation. This account operates differently at polity and district levels, prompting us to construct separate theoretical accounts. For polities, we surmise that size alters incentives for leaders and masses, both of whom have greater need for an institutionalized mechanism of resolving conflict. In districts, we argue that scale influences contestation through mechanical effects, the supply of challengers, and the degree of social diversity. Next, we introduce our data and a variety of empirical tests, including cross-national and cross-district analyses based on the largest-party index. In addition, we provide an analysis of suffrage reforms and turnover, understood as a change in party control for a particular office. Although the topic has not been extensively researched, most studies that examine the relation – including our own results presented in this chapter – find a positive association between community size and contestation. A short conclusion summarizes the results.