The features of using Role-playing games in educating students - prospective teachers are considered. In practical classes on teaching methods of various disciplines, Role-playing games are often used, associated with conducting a fragment of a lesson or a full lesson. Typically, these practical classes are organized on an empirical level. The version of the Role-playing game "Observing Mathematics Lessons", developed on the basis of the theory of contextual learning, is presented. Psychological and pedagogical principles: simulation of specific conditions, game modelling of the content and forms of professional activity, collaborative activities are used in the design of the game. These principles are the basis for creating a game model, which consists of: game goals, a set of roles that indicate the functions of the player, the scenario and the rules of the game. The simulation model contains: didactic goals, the subject of the game and the evaluation system. An important difference developed by the Role-playing game is to take into account the personality types of students - participants in the game. Students with personality types typical for STEM students were selected for the role of "good pupil”. The roles of the "bad pupils" were played by students with personality types typical for students who usually do not have academic success in mathematics. A survey has been conducted, which showed that the proposed Role-playing game enable the simulation of the real situation of an observing mathematics lesson.