From the introduction: Eruption! is a volcanic crisis simulation model that showcases a series of villages that surround an active volcano that is part of the Interactive Models for Geological Education Online (IMGEO) series. The goal of the exercise is to preserve as many people and as much property as possible in spite of the threat from the volcano. Students role-play as villagers, the governor, volcanologists, or the press. Guides for teaching assistants and students, and the rules of the simulation are available on the site. Three different versions are downloadable, for different hardware and classroom situations (e.g. one computer per student, one computer and multiple students, and a networked environment). The activities in each are modified slightly to reflect the level of computer access for the student.