Role playing is an important element of virtually all simulation-based procedures. An improved understanding for methodological aspects facilitates its goal-oriented use in education and training, research and examinations. In the present paper we describe how different forms of role play are used in different simulation-based procedures. We describe a plausibility study from skills labs demonstrating that the introduction of role-playing can increase perceived realism. Finally we derive practical suggestions for the conduction of role plays in medical simulation.