The Model United Nations format is one of the most popular active learning techniques to teach students about the evolving system of global governance and the limits of international organizations. In a world where the UN must cooperate with a variety of actors in the international system to address global challenges, students can benefit from simulations that draw on the intergovernmental Model United Nations format, but move beyond it to explore the complexities of negotiation involving state and nonstate actors. This paper discusses the use and development of a simulation for an upper-level international organization course loosely modeled on the XV International AIDS Conference held in Bangkok, Thailand in July 2004. It explores the value of the simulation, including learning objectives and expectations, student preparation in advance of the simulation, post-simulation debriefing, and an assessment of how the simulation can be modified and made more effective.