With the appearance of the Eleventh Edition, this book is now well into its sixth decade. Throughout its long history, this casebook has relied on classic cases to capture the fundamental principles of contract law. This new edition preserves and builds upon the book's distinctive character, especially its use of canonical cases and its sensitivity to the history. The newly added cases show how the basic principles of contract law continue to evolve, even in such well-explored areas as promissory estoppel and restitution. As before, this edition eschews any distinctive take on the law of contracts and thus allows each teacher using the book a broad range of choice on what to bring in to channel or expand classroom discussion. The most visible alteration in this edition is a new focus on the bargaining environment in which contracts are formed and how legal rules shape it. A significant amount of new material has been added, but the length of the book remains about the same.