Over the last quarter century, crisis bargaining has become the prevailing paradigm for the study of war. This textbook presents a concise and approachable overview of the crisis bargaining literature, surveying the canonical formal models in the bargaining approach to war. It begins by considering different explanations for war, then delves into two classes of explanation: commitment problems and incomplete information. This textbook is essential reading for advanced undergraduates, graduates, and researchers alike. Each chapter delves into a specific part of the puzzle, rigorously unravelling the twisted logic that causes wars to begin. More than seventy illuminating figures illustrate the strategic reasoning outlined and more than 100 exercises of graded levels of difficulty help clarify readers' own understanding of the issues. Online resources include an instructor answer key and numerous engaging video lectures.