Tiny Towns: Underground

Its square can hold one resource named by another player. You can use that resource in a building layout under the normal construction rules; after you build, the square can hold one resource again (rulebook, p. 4).

No. A building needs an empty square for its building token, so Underground resources alone can’t complete a building layout (rulebook, p. 4).

If you’re placing the Underground building without using resources, you can’t place it on a square that already contains a resource (rulebook, p. 4).

If you’re playing with Tiny Towns: Villagers, no—you don’t have to move a working villager when placing a resource on an Underground building square (rulebook, p. 4).

The rules recommend using no more than three buildings with the Underground ability. You can use Turf Home instead of Cottage, or shuffle the blue cards for a randomized setup (rulebook, p. 3).

Sanctuary scores at most 4 points: 2, plus 2 if it is both adjacent to at least one empty square and adjacent to exactly one empty square (rulebook, p. 5).