When an economic collapse, natural disaster, epidemic outbreak, terrorist attack, or internal crisis puts a country in dire need, governments must rise to the occasion to protect their citizens, sometimes employing the full scope of their powers. How do political systems that limit government control under normal circumstances allow for the discretionary and potentially unlimited power that such emergencies sometimes seem to require? Constitutional systems aim to regulate government behavior through stable and predictable laws, but when their citizens' freedom, security, and stability are threatened by exigencies, often the government must take extraordinary action regardless of whether it has the legal authority to do so. In Extra-Legal Power and Legitimacy: Perspectives on Prerogative, Clement Fatovic and Benjamin A. Kleinerman examine the costs and benefits associated with different ways that governments have wielded extra-legal powers in times of emergency. They survey distinct models of emergency governments and draw diverse and conflicting approaches by joining influential thinkers into conversation with one another. Chapters by eminent scholars illustrate the earliest frameworks of prerogative, analyze American perspectives on executive discretion and extraordinary power, and explore the implications and importance of deliberating over the limitations and proportionality of prerogative power in contemporary liberal democracy. In doing so, they re-introduce into public debate key questions surrounding executive power in contemporary politics.