This book is now my favorite negotiations book, not only does it give a clear framework of what to do when you encounter opposition in a negotiation it also enlightens the reader on the benefits of negotiation. This is a much more enjoyable book than Getting to Yes: Negotiating Agreement Without Giving In, but reading Getting to Yes is essential but not required.
If you seem to come to negotiation circumstances and feel that you did poorly or caved in, then you need to read this book. If you feel cheated or unable to articulate a response to an argument,then you need to read this book. If you want to take a negotiations class and you think your are not good, then you need to read this book.