User summary: Systema Tartarobasis is a science fantasy adventure module written by Gábor Lux for World Adventure Writing Month 2007. The module is statted for Castles & Crusades (the designer states in the introduction that it should be easily converted to any of several other sets of fantasy/planetary romance rules systems). The campaign in this book is quite detailed and includes an illustration booklet, maps and several appendices detailing new creatures/monsters, important NPCs and cultural aspects reflected in the adventure. The adventure puts characters in unfamiliar environments and situations as they move deeper into the ruins of technologically advanced subsurface cities.