Age of Ravens: History of Cyberpunk RPGs (Part Two: 1993-1994)

Underground (role-playing game) - Wikipedia

Resistance underground (RPG map) by ndvMaps on DeviantArt

Mendel Palace — Front cover (by Geof Darrow) and some interior

Pyramid: Pyramid Pick: Underground

Battlelords of the 23rd Century (Military Sci-Fi RPG, 7th edition) by 23rd Century Productions, LLC - Galactic Underground 2 (6th Edition) - Gamefound

Fully Strapped, Always Packed RPG book gats and gear from the underground mfg

Underground Caves Thematic Dungeon Terrain DND Pathfinder

Underground RPG

Underground Warehouse Fantasy Digital Battle Map – RPGxNihilo

d&d underground megadungeon map, Stable Diffusion