INTRODUCTION: "Simulation Roulette" is a new method of "on-the-fly" simulation scenario creation that incorporates a game-like approach to critical scenarios and emphasizes prescenario preparation. We designed it to complement our traditional anesthesia simulation curriculum, in which residents are exposed to predefined "critical" scenarios. During typical scenarios, trainees are often given minimum preparatory information; they then start the scenario knowing only that "something bad" is going to happen. As a result, trainees often report anxiety, which can be a barrier to learning. To overcome this barrier and to augment traditional critical incident training, we developed the "Simulation Roulette" game. METHODS: "Simulation Roulette" consists of premade cards that are randomly selected to create a patient, another set of premade cards to assist in selecting "complications," worksheets to guide a thorough "prebrief" discussion before the scenario, and scoresheets to facilitate the "debrief" discussion at the end. Similar to traditional scenarios, it requires coordination by a facilitator to ensure plausible scenarios and evaluation of trainee performance. RESULTS: Although we have not conducted formal testing, we believe that (1) incorporating an element of random chance to scenario selection, (2) using a game-like framework, and (3) emphasizing the "prebrief" portion of simulation all have the potential to decrease trainee anxiety. CONCLUSIONS: We present the rationale for designing such a game; examples of instructions, cards, and scoresheets; and our initial experience with implementing this game within our simulation curriculum.