Our research deals with the development of a new type of game-based learning environment: (M)MORPG based on mixed reality, applied in the archaeological domain. In this paper, we propose a learning scenario that enhances players' motivation thanks to individual, collaborative and social activities and that offers a continuous experience between the virtual environment and real places (archaeological sites, museum). After describing the challenge to a rich multidisciplinary approach involving both computer scientists and archaeologists, we present two types of game: multiplayer online role-playing games and mixed reality games. We build on the specificities of these games to make the design choices described in the paper. We also present three modular features we have developed to support independently three activities of the scenario. The proposed approach aims at raising awareness among people on the scientific approach in Archaeology, by providing them information in the virtual environment and encouraging them to go on real sites. We finally discuss the issues raised by this work, such as the tensions between the perceived individual, team and community utilities, as well as the choice of the entering point in the learning scenario (real or virtual) for the players' involvement in the game.