This book looks at thirteen different legal systems, ranging from Imperial China to modern how they worked, what problems they faced, how they dealt with them. Some chapters deal with a single legal system, others with topics relevant to several, such as problems with law based on divine revelation or how systems work in which law enforcement is private and decentralized. The book’s underlying assumption is that all human societies face the same problems, deal with them in an interesting variety of different ways, are all the work of grown-ups, hence should all be taken seriously. It ends with a chapter on features of past legal systems that a modern system might want to borrow.