Motivated by the challenge of combining psychological theories and methods with high-tech gaming and simulating technology, a project was carried out to develop a simulator that could train people in the skill of negotiation. An analysis of the existing theory, interviews with experienced negotiators and observations of negotiation in action formed the basis for a User-Centred Design process. Through the application of Contextual Design methods, traditional qualitative methods, and a Usability test, this process has currently resulted in the overall design of a training program and an early design prototype. As well as this, the project served as a testbed for an exploratory study of the application of User-Centred Design methods to the development of a training simulator. This type of development poses new requirements for user-centred methods, as the simulator will support a different context of use than the one analysed to inform its design. The study suggests a possible approach to user-centred development of simulator-based training, founded mainly on Contextual Design and Cognitive Work Analysis.