Principled negotiation is a type of bargaining that focuses on mutual interests and finding mutually beneficial outcomes. There are four key elements: mutual gain, focusing on interests rather than positions, separating emotions from issues, and using objective criteria. Team and multiparty negotiations involve multiple people on each side and present additional challenges around fluctuating alternatives and coalition formation. An adversarial approach focuses on hard bargaining and achieving the most aggressive party's interests, while neglecting the other side's problems and interests. Overcoming biases around one's own viewpoints and perceptions of the other side can help reach mutually agreeable solutions.