From the publisher:
Look Out Below!
Some adventurers are down-to-earth . . . and some go even further! With GURPS Underground Adventures, you'll explore the dark downward domains like never before. In this well-grounded supplement, you will . . .
Discover a sampling of what people around the world have thought about Earth, from early legends to modern speculations. It has an overview of current information about Earth's interior . . . plus details on what it would take to destroy the planet!
Come to understand the hazards of traveling underground and how to overcome them: the restrictions on the senses and movement, the dangers of water and air, the characteristics of different kinds of caves, and more.
Don one of five templates for underground explorers, and get details on important gear and vehicles. Find tips for GURPS traits particularly suited for subterranean adventurers, including new Talents, techniques, and spells.
Become familiar with several different kinds of fantastic underground creatures through information on their species and game stats.
Learn how to add subterranean locales to settings – or use one of the genre seeds to begin a campaign underground!
GURPS Underground Adventures proves that if you find yourself in a hole, keep digging! You're bound to discover adventure . . .