SYSTEM-NEUTRAL, D20 based.
- Over 70 maps
- Over 130 illustrations by Justin Sirois and Scott Buoncristano
- Over 100 hours long
- 1D100 abominations to battle inside The Invert
- Random maze generator to create endless hallways, enemies, and loot
Includes Beneath, the Inverted Church (book 1), Beneath, the Spire and the Sound (book 2), and the monster manual Pleasures & Pestilence.