This law school casebook is intended for use in a basic course on the substantive criminal law. The major emphasis in this casebook is upon what is usually referred to as the "general part" of the criminal law, mental state and act, responsibility, justification and excuse, inchoate crimes and liability for the conduct of another. There is also special emphasis upon the actual and potential contributions of the legislative branch in resolving the difficult policy questions that exist in this field. This sixth edition differs from its predecessor largely by enrichment of the Notes and Questions throughout the book with excerpts from over 100 new appellate cases and over 50 recent law review articles.