Abstract: Based on the author’s years of classroom teaching and extensive experience consulting at major law firms, this book is organized around actual problems that routinely occur in practice. It does not pretend that such problems are solved by the mechanical application of rules, although all important and relevant rules are included. Rather, these problems are seen in the context of decided cases, academic articles, and the overriding principles of ethical philosophy, adding a dimension missing from many professional responsibility texts. This edition includes important changes in the ABA and Massachusetts rules and adds some excellent new cases that are of value in navigating the ethical pitfalls of the real world.