No subject is more central to the study of politics than elections. All across the globe, elections are a focal point for citizens, the media, and politicians long before—and sometimes long after—they occur. Electoral systems, the rules about how voters’ preferences are translated into election results, profoundly shape the results not only of individual elections but also of many other important political outcomes, including party systems, candidate selection, and policy choices. Electoral systems have been a hot topic in established democracies from the UK and Italy to New Zealand and Japan. Even in the United States, events like the 2016 presidential election and court decisions such as Citizens United have sparked advocates to promote change in the Electoral College, redistricting, and campaign-finance rules. Elections and electoral systems have also intensified as a field of academic study, with groundbreaking work over the past decade sharpening our understanding of how electoral systems fundamentally shape the connections among citizens, government, and policy. This volume provides an in-depth exploration of the origins and effects of electoral systems.