While sustainability is increasingly recognized as an important ethical principle, teaching ethical reasoning skills appropriate for sustainability is problematic. While the classic approach in professional ethics education makes intensive use of behavioral codes and retrospective case studies, these approaches are limited in their ability to prepare students for the unfamiliar and forward-looking problems of sustainability. Moreover, the classic read-discuss-write pedagogical strategies typical of the humanities emphasize abstraction and reflection at the expense of two modes of learning more familiar to many professionals (e.g., engineers and physical scientists): experimentation and experience. This paper describes the results of a novel experiential approach to ethics education that employs non-cooperative game theory to position students in situations that model unfamiliar ethical tensions characteristic of sustainability problems, such as the Tragedy of the Commons. In this approach, students can only advance their own grade at the ultimate expense of other students. Whereas the Nash Equilibrium in our games predicts systemic collapse of student grades, the actual grade outcomes aligned with egalitarian ideals, despite evidence of conflict in on-line student communications.