Mining Damage

The amount of damage inflicted on structures above by a collapsing mine depends on the volume of the gallery and the terrain on which the castle stands. A collapsing gallery inflicts the following number of hits for each 1,000 cubic feet of gallery volume:

Earth	2d8
Soft Earth	1d8
Hard Stone	1d6

For example, a castle is built on soft stone. The attackers have excavated a gallery 20’ wide by 30’ long by 10’ high (6,000 cubic feet) beneath one of the walls. If the gallery is successfully collapsed, it will inflict 6d8 hits on the wall above.