We report an investigation of the sociolinguistic characteristics of simulated encounters (role plays) in medical education, focusing in particular on frame negotiation. The role played by context in influencing the nature of out-of-frame activity is noted through comparison with another published study of simulations (Linell and Thunqvist 2003). While in general sustaining a role-playing frame that involved an orientation to exact mimicry of clinical situations, the interactional work done to sustain this appearance of 'authenticity' at certain moments was revealed by out-of-frame utterances. One participating doctor in particular used humor to exploit the ambiguous realism of the role-playing frame. The success of this doctor in acquiring and applying new communication behaviors problematizes the view that 'realism', achieved through mimicry, is solely responsible for the success of training interventions. The implications for studying other kinds of simulated encounters, including an outline for a program of research into the sociolinguistics of acting tasks in general, are outlined. Sociolinguistic researchers involved in observational studies of talk would benefit from adopting the view that role-played, rehearsed, and even scripted talk of the sort used in dramatic performance is a variety of naturally occurring data and therefore worthy of study.