Negotiation is a problem-solving technique that helps lawyers resolve disputes with opposing parties. It is the process of reaching mutually agreeable terms for a settlement or transaction. There are common elements, stages and principles that apply across different situations and even cultures. This chapter introduces the basic principles of negotiation, including the common stages of the process, the key points of successful negotiation, the difference between interests and positions in the negotiation process, and the main criteria of Principled Negotiation. The chapter presents the three familiar models of negotiation, all of which are relevant to the practice of law: soft, distributive and principled negotiation, which are evident in the chapter about the Canadian National Negotiation Competition. The chapter concludes with some of the common errors of negotiation, criticisms of principled negotiation, and a brief commentary about the role of negotiation in international conflict.