Unconventional learning activities such as games and simulations have been widely used as teaching tools in international relations (IR) in the recent years. The literature on simulations and student learning has often highlighted a lack of empirical evidence in the existing research. The paper aims at providing empirical support to illustrate the ways in which simulations might influence students' levels of (factual and self-evaluated) knowledge and perceptions of IR. The study is based on extensive empirical material, collected through questionnaires submitted to 298 students who participated in the 2014 edition of the National Model United Nations in New York (NMUNÁNY). Keywords Simulation Á Model United Nations Á Perceptions Á Knowledge Á IR Despite the growing use of games and simulations as teaching methods in international relations (IR), the existing research has produced a limited number of empirical studies (Giovanello et al. 2013). ''Although many educators realise the potential benefits of games and simulations as pedagogical tools, few researchers have examined their use empirically'' (Garard et al. 1998, p. 42). In addition, the current empirical studies deal more frequently with students' evaluation of the simulation itself rather than with the actual change in the level of knowledge or of perceptions that students experience during the simulation. On the contrary, this paper addresses how and to what extent participating in a simulation affects & Fabrizio Coticchia