This gamebook follows 8 of the 12 tribes (Outdoor, Egyptian, Highland and Cavelem are not featured) of Lemmings 2, as they try to find their parts of the Great Medallion. In the video game the Lemmings are trying to bring all the parts to put it back together, so the events in the book can be considered to have taken place before those in the game.

You start with 50 lemmings, and each zone requires then to be assigned to various skills (recognisable from the game, so the Classic zone have Blocker, Builder, etc - although bizarrely also Ballooner and Filler). You then choose options and use skills in various ways to guide the lemmings to their piece of the medallion. The lemming skills don't generally get "used up" so it's possible to take along a skill assigned to a single lemming and use it multiple times unless the book expressly forbids it. All the zones are thematically correct for the tribes, and once you've successfully navigated them to the medallion you get an extra five lemmings. They are a lot harder to lose than in the game!

To complete the book, all eight zones need to be successfully completed.