Underworld affects the Overworld

[Vnalor]

Cave-ins from a level 1 cave system should reflect the damage above, showing sunken ground on the surface. This will generate cliffs as well.
The same thing happens for lower levels - if Level 2 Cave has a cave-in, Level 1 Cave will sink and cause another cave-in (although greatly reduced in scope)
Significantly raises the necessity of mine supports.

Cave-ins from much lower levels (let's say from Level 5), will still have a great effect, but may stop midway between Level 3 or 2, depending on how severe the cave-in is. Therefore, it wouldn't reflect much on the surface since it stopped caving in underground. Although this is only possible if cave-ins were weaker than usual, which wouldn't be in case this idea is implemented.

Trolls now have the leverage of fucking up whatever exists outside their normal range, far above their subterranean dwellings. They can now cause unwary foragers to fall to their deaths by being aggroed by a miner who has not befriended them.

[Dawidio123]

+1, can't see this being used in nefarious ways

[Massa]

now this is definitely the kind of post i expect from gay furry jesus with 50 posts

[dafels]

Yeah it would be cool to cavein a village from below

[terechgracz]

What about Aboveworld