; You fail to produce anything here. The rock is stone hard. : Occurs on the surface. This means the tile you are attempting to excavate is actually an ore vein. There's nothing to do about it, you simply have to make your entrance on another tile. Note that if you make the entrance one tile below the vein, the tunnel will open right into the vein and cannot be extended until the vein is depleted.
; The ground sounds strangely hollow and brittle. You have to abandon the mining operation. : Occurs on the surface. This means there's already a tunnel on the tile you're trying to excavate. There's nothing to do about it, you simply have to make your entrance on another tile. Or you could search for the entrance (possibly caved in) to the existing tunnel.
; The cave shudders from some imbalance.: Appears when you are mining into another mine shaft and the height difference is not dangerous.
; The cave wall sounds hollow.
; ? A dangerous side shaft will appear. : Occurs inside a mine. This message appears when the tile you are excavating shares a single corner with an existing tunnel. To excavate it you must first excavate so the target tile shares an entire wall with the other tunnel. See example on the right.
; The cave walls look very unstable. You cannot keep mining here. : Occurs inside a mine. Exact cause unknown, it happens when mining close to the top of the rock layer, and can sometimes be avoided by mining downwards.