Spoilers

Digging below the colony

Dig stairs to connect levels. A shaft plan creates stair orders down one column, and miners work from the top down. An obstructed landing stops the stair above it. Inspect the landing before starting a second shaft beside the first.

The deep column reaches 24 levels below the surface. Its bands run from the Bedrock through the Deep Stone and First Caverns to the Fossil Galleries, Flooded Stair, Hearth, Crystal Lattice and Undermaw. Ore and creature selections vary by band.

Dread rises below the Bedrock, with extra pressure from isolation and sleeping deep underground. Ordinary settlers get relief from the surface, shallow cellars, suitable light and company. Check the person’s dread causes before leaving them down there for long shifts.

Long exposure can permanently change a settler. Time in the Crystal Lattice also has its own cumulative effect, which slows the body and can eventually make the settler go still. Leaving stops further Lattice exposure, but does not erase what has already accumulated.