Some recent science education scholarship has called for a renewed focus on empowering learners to engage with science for personally and socially meaningful purposes. However, engaging with science in these ways requires that learners adopt epistemic aims in their activity, which we cannot take for granted. I argue here that serious games could support these goals, but that our approaches to their design and implementation require greater attention to the cultural and historical aspects of the activity systems in which they are being used. Attention to these elements provides us with powerful tools for situating our designs in use contexts. [For the complete volume, "Educational Media and Technology Yearbook, Volume 39," see ED594284.]