Location from He Who Fights with Monsters by Shirtaloon
Pocket dimensions attached to worlds — the spaces between reality that the Builder steals and adventurers delve for profit and survival.
Astral spaces are where much of the series' adventuring happens. They're pocket dimensions with their own internal rules, monsters, and sometimes intelligence. The Adventure Society manages stable ones as training grounds and resource sites. Unstable proto-astral spaces are hazards that require immediate response teams. The Builder's grand plan involves stealing astral spaces from worlds, giving them brief self-sustaining capability, and anchoring them to its constructed world in the deep astral. This makes every astral space both a resource and a potential target.
Each astral space is unique — some are dungeon-like labyrinths, others are open landscapes, some are abstract geometries that defy normal physics. They exist as pocket dimensions attached to Pallimustus and other worlds, invisible from the outside until entered. Unstable ones (proto-astral spaces) can collapse or merge with reality unpredictably.
Also known as: Astral Spaces, Pocket Dimensions