Plumb the Depths of the Underdark
A dungeon is a living, thriving environment full of creatures that mostly need to eat, drink, and breathe. How do they get their fresh air? Where does their energy come from? And where do they go when they need to... go? When you ask yourself these questions, your dungeon becomes more alive and tangible.
In this book you will find a wealth of ideas and provocations to help you transform your subterranean spaces, from the physics of cave formation to the ecology of underground plants; from the reproductive habits of purple worms to the timekeeping systems of the drow. You will discover how the Underdark is periodically overrun by census-taking modrons or swarms of blind locusts, and the mystery of D&D's confusing economics is finally cleared up.
And because these are fantasy worlds, throughout you will also find dozens of new monsters, NPCs, and magic items with an exotic but practical flavor, ready to drop into your own campaign. Discover parasitic insects like the Dragon Botfly, predators like the pack-hunting Skuttle, and helpful elementals like the playful Nozzle. Find how Underdark communities use magic to solve their day-to-day problems in areas like bureaucracy and agriculture. And meet the Maintenance Crew, four roving NPCs with skills to spare.
- from the publisher's blurb