History is replete with instances of what might, or might not, have been. By calling something contingent, at a minimum we are saying that it did not have to be as it is. Things could have been otherwise, and they would have been otherwise if something had happened differently. This collection of original essays examines the significance of contingency in the study of politics. That is, how to study unexpected, accidental, or unknowable political phenomena in a systematic fashion. Yitzhak Rabin is assassinated. Saddam Hussein invades Kuwait. Hurricane Katrina hits New Orleans. How might history be different had these events not happened? How should social scientists interpret the significance of these events and can such unexpected outcomes be accounted for in a systematic way or by theoretical models? Can these unpredictable events be predicted for? Political Contingency addresses these and other related questions, providing theoretical and historical perspectives on the topic, empirical case studies, and the methodological challenges that the fact of contingency poses for the study of politics. Contributors: Sonu Bedi, Traci Burch, Jennifer L. Hochschild, Gregory A. Huber, Courtney Jung, David R. Mayhew, Philip Pettit, Andreas Schedler, Mark R. Shulman, Robert G. Shulman, Ian Shapiro, Susan Stokes, Elisabeth Jean Wood, and David Wootton.