Only a few of the following examples are actually ready-to-run in an undergraduate classroom, but they will provide inspiration and materials for your own role-playing exercises. Many of the scenarios, characters, and assignments need a few added details, which will enable you to tailor them to your course.
The Grand Canyon part of Pedagogy in Action:Library:Role Playing:Examples
This interdisciplinary lesson plan deals with the consequences of damming in the Grand Canyon area. The students, role-playing as scientists, write a proposal to try experimental flooding.