2017 · ソースブック（プレイを拡張するルール／オプション）

Underworld Races & Classes (Pathfinder)

This Pathfinder companion expands adventures in an underworld setting with 14 new playable races and more than 25 classes, archetypes, and class options. It details cultures such as the drow, four-armed hoyrall, crocodile-like kraidyl, funglets, and quasi-undead halflings. The book also includes optional sonar-based perception rules, scaling guidance, feats, favored class options, equipment, monsters, spells, and setting-specific elements such as symbiotes, spores, soul candles, web-slinging, and explosive mushrooms.