Literacy researchers have explored how video games might be used as supplementary texts in secondary English language arts (ELA) classrooms to support reading instruction. However, less attention has been focused on how video games, particularly online educational games designed to teach argumentation, might enhance secondary ELA students’ writing development. In this article, we describe how the pedagogical feedback provided by one such game, Quandary, influenced two seventh graders’ written arguments in advocacy letters addressed to the state governor regarding a local environmental disaster. We compare these two embedded cases to data from 10 focal students, as well as patterns from 114 seventh graders (in five ELA classes). Based on our analysis of screen-capture video of students’ gameplay, drafts of their advocacy letters, and video-stimulated recall interviews, we conclude that game feedback rewarding or penalizing predetermined right or wrong player moves may encourage students to develop argumentation strategies that are less effective in more complex rhetorical situations and may foster a false sense of competence.