At some point in almost every serious negotiation, someone will say something that sounds like a door slamming shut. This is not negotiable.
Your task is not to challenge legitimacy prematurely, but to understand which kind of constraint you are dealing with. In this section, we look at the two-step diagnostic process, the importance of self-reflection before responding, and how to evaluate the strength of your BATNA.
Understanding of the difference between visible goals and the underlying interests, values, and motivations that drive them. It's important to distinguish the reasons because for every reason there is a different path to reaction.
In summary we hope to have led you to a point of clarity in any negotiation where someone says “this is non-negotiable”: will you succeed in this negotiation, or will you walk away.