Active learning is a more effective approach than passive learning, and formats such as role-playing games (RPGs) can be more effective still due to perspective shifting that students undertake during participation. This is especially the case for environmental and geosciences education, but to date, RPGs are sparsely used in this space and when they are, they tend to be highly specialized and non-generalizable. Here we will describe Sustainable States, a general purpose RPG developed for environmental diplomacy education which features learning objectives in Earth sciences, political sciences, and soft skills. Sustainable States has been deployed at several universities globally and we will specifically describe the outcomes at two (Arizona State University in the USA and Universidade Estadual de Campinas in Brazil). Although requiring additional work to simplify game rules and help students achieve the stated learning objectives, initial results show high levels of engagement and strong potential to become a powerful general education tool for environmental and geoscience topics.