While literature exists on the use of classroom simulations to teach international relations (Kaufman 1998; Lantis 1998; Wilkenfeld 2004; Asal 2005), there is a tacit assumption that students engage primarily as participants. Remaining relatively unexplored are the learning dynamics when students become responsible for simulation design. This paper addresses this gap in the literature via an examination of PSCI 494—“Wargaming and Simulation,” a senior seminar focused on design principles for war games and role-based simulations. The students' project (2010) was to create a simulation for the International Communications and Negotiations Simulations project. From the experience, this paper concludes that simulation design is a valuable active-learning strategy with regard to negotiation; course length and class size both strongly impacted the process and product created in the course; and a range of skills, especially research, were enhanced as a result of the project.