This classic casebook has been thoroughly updated for 2020–retaining what has made it a favorite for decades while also remaining current and user-friendly. As ever, it contains lightly-edited cases with extensive explanatory notes, thereby teaching students how to read cases while learning doctrine. Some notes are historical and comparative, giving students a more nuanced understanding than can be obtained from simply studying current law. The book is accessible without sacrificing interest and complexity, providing a sophisticated understanding of civil procedure and the federal system. The book also remains adaptable to courses of different length and emphasis, and teaching the material in the instructor’s preferred order. The twelfth edition has been thoroughly updated with extensive new material on personal jurisdiction, multidistrict litigation, the amended discovery rules (with a new exercise), and mandatory arbitration.