Games are omnipresent for children and young people. In primary and secondary schools in Switzerland, however, games still eke out a niche existence. Topics such as Game Design, Serious Games, or the Game Culture in general offer enormous potential for teaching, and there are many ways for pupils to experience the world of games together. However, specific training programs for teachers are necessary. For many teachers, these topics are less tangible than they are for children. To develop a new curriculum for in-service teachers, this paper addresses the prerequisites for a transversal games-curriculum for primary and secondary schools in Switzerland. In this endeavour, first, links between games and the Swiss Curriculum 21 are presented. Second, recent literature on games in the school context is reviewed, and finally, interviews with teachers on their beliefs and ideas about digital games are analysed. The results show that although teachers often have a limited idea of games in the classroom, they consider the topic relevant and sometimes already use game-based approaches.