This article critiques existing educational literature in relation to simulations, identifying some methodological flaws in the relevant empirical studies, but also pointing to a strong correlation between simulations and student engagement in studies involving a range of methodologies. The article contributes to this literature by presenting the findings of empirical research related to the conduct of a treaty simulation based on the ongoing negotiations under the recently concluded Paris climate agreement. It also provides a step-by-step guide to conducting a treaty simulation, including links to the required materials. Possibilities for student assessment of this simulation are provided and analysed, as well as proposals for adaption of the simulation to different subject areas.