How can we better design games, such as role-playing video games (RPGs), to support the practice of ethical thinking? Ethical thinking is a critical component of twenty-first century citizenship and we need to design ways to creatively support its practice. This study investigates how male participants, ages 18-34, make ethical decisions in three in-game scenarios in "Fable III," an RPG, and one additional scenario. The decision-making processes of thirty participants were analyzed; twenty were randomly assigned to play "Fable III "and ten were assigned to a control condition of written ethical scenarios. Results suggested that participants practiced a variety of ethical thinking skills and thought processes in both conditions, including reasoning-, empathy-, reflection-, and information gathering-related skills and thought processes. Three hypotheses were investigated and detailed, and any significant differences or similarities that emerged between conditions and across game scenarios were explored. Based on this analysis, four preliminary design principles were described.