The Forgotten Underground Cities are the deep-civilisation layer of Fatekeeper's world: built sites that pre-date the present surface and now sit empty, partial, or repurposed beneath the world the player walks above. They are tied to the longer Past Cataclysms arc and to the displaced Underdwellers who shelter in the network the cities left behind. The Mar 2026 dev material framed this layer as a major exploration target rather than a single-zone curiosity.
What These Cities Are
These are not natural caves. They are engineered, paved streets, stonework, structural columns, gates, and the bones of an extinct city plan. The team has framed them as remnants of a culture that built down rather than out, leaving a vertical record of the world's earlier civilisations. They sit in the same continuum as the Technocratic Society, partial survivors, partial ruins, partial wreckage from events the surface has mostly forgotten.
Relation To The Underdwellers
The Underdwellers are not the original builders of the cities; they are the displaced survivors who have settled inside the spaces the cities left. The relationship between the displaced population and the architecture they inhabit is one of the central Surface vs Underground Conflict tension points: the cities give shelter and resource access, but they also carry the residual presence of whatever caused the cities to empty in the first place.
Hazards
The Forgotten Underground Cities are not safe. The hostile populations the player encounters there include but are not limited to:
Husks, corrupted remnants of original occupants.
Corrupted Wildlife, creatures changed by long exposure to the deep environment.
Arcane Wielders, magic-users whose practice survives in these spaces.
Shortlings, a smaller-frame enemy population that has adapted to underground life.
The underground layer is also where some of the more exotic Bosses of the campaign live; the team has signposted that several of the high-stakes encounters take place inside these cities rather than on the surface.
Connecting Routes
The cities connect into the wider network of Underground Caverns, the natural cave systems that wrap around and run between the engineered sites. A typical underground expedition will move between cavern stretches and city stretches; the cavern stretches handle traversal and ambient hazards while the city stretches handle structured encounters and lore payoffs.
Lore Payload
The cities are where Fatekeeper's deep-history exposition is most concentrated. They preserve:
Built records, stonework, inscriptions, layout patterns that reveal who lived here.
Practitioner ruins, sites where the Technocratic Society left functional or semi-functional artefacts.
Cataclysm-era debris, physical evidence of the events on the The Surface Cataclysm page.
Why The Player Goes Down
The cities are not a dungeon optional side-track; the campaign passes through them. The team has framed several mid-to-late campaign arcs as descents, the player has surface objectives that route them through the underground, where the deeper lore and the larger threats actually live. Refusing to go down means missing both story and high-value loot routes.
Tonal Note
These spaces carry the heaviest atmospheric pressure in the game. The dark fantasy register lands hardest down here, close walls, distant sounds, low light, and the presence of populations that read as part-people, part-something-else. The Talking Rat companion's narrative function is most visible inside the cities, where the close architecture gives the small-creature framing of the companion a practical reason to be there.
Open Questions
Whether the cities span one continuous map layer or several disconnected regional networks is not fully spelled out.
Whether the player can build, claim, or shelter inside a city node is not confirmed.
How the technocratic-era artefacts interact with the player's Skill Tree or Magic is hedged in the published material.
Related Pages
The Underdwellers, the inhabitants.
Underground Caverns, the natural connecting network.
Past Cataclysms, the deep-history arc.
The Surface Cataclysm, the specific surface event.
Surface vs Underground Conflict, the framing.
Technocratic Society, the original builders.
Lore Overview, index.