In this article, the authors describe a simple classroom game that demonstrates the advantage of tradable emissions permits in regulating environmental pollution. Students take on the role of polluters who must consider the costs of complying with a uniform reduction and a tradable permits program. The class is divided into high-cost polluters and low-cost polluters so students can observe the gains from trade as high-cost students purchase pollution rights from the low-cost students in the tradable permits scenario. A major advantage of the game is that it can be conducted within as little as 20 minutes and does not require that students have prior knowledge of economics or regulatory policies. This makes the game appropriate for economics and noneconomics courses alike.