Instead of trying to fit a theory or create a new theory to the empirical evidence, this chapter outlines a number of tools from negotiation and integration literature which are useful in describing and analysing IGC negotiations. The aim is to highlight key issues and characteristics of the negotiating process of an IGC and thus provide a road-map for analysing the events leading to the institutionalisation of flexibility in the Amsterdam and Nice treaties. The book explains how things change in an IGC and outlines an array of ideas, interests and issues at stake for the actors in the 1996–97 and 2000 IGCs’ negotiations on flexibility.