Simulations are increasingly common pedagogical tools in political science and international relations courses. This article develops a classroom simulation that aims to facilitate students' theoretical understanding of the topic of war and peace in international relations, and accomplishes this by incorporating important theoretical concepts about the causes of war found in international relations theory into the design and implementation of the simulation. In addition to sharing a successful classroom simulation with other international relations instructors, the article makes two important contributions to the pedagogical literature on simulations. First, it shows how simulation design can be usefully based on the theoretical concepts and/or substantive problems that course instructors aim to impart to their students. Second, it demonstrates that it is possible to achieve important learning objectives with low-intensity simulations that do not require a big investment of time, energy, and resources.