Learning games are interesting environments presenting factual advantages. New usages emerge for learning and we need to consider them for the design of these games. Collaborative support, observation capacities and immersion are aspects that are directly linked with these learning environments. In this paper, we focus on the "immersion" feature and we propose some guidelines in order to take it into account as much as possible while designing an educational game. In order to illustrate our purpose, we present a learning role-playing game "World of SeRéCom"