While there are several positive outcomes from implementing game design in a formal learning context, there are also challenges that have to be considered in order to improve game-based learning. This is explored in the article, using the concepts of "activity frames" and "stancetaking", focusing on the social organization of the game design activity. Building on video data from one 6th grade class and one 7th grade class designing computer games based on their social studies curriculum, this article shows that tensions arise when students fail to agree on what the activity they are doing is really about: The academic content and what students commonly perceive as school activities, or a game design activity informed by their leisure time. The main argument is that the students position themselves as "students", "game designers" or "characters", and that this may cause tensions in the students' social interactions.