Setup & compatibility
Do I need a fresh world? No. Nothing changes until someone digs.
Does everyone need the mod? Yes. Server and every client, same version, or you get kicked. That means no crossplay.
What if I uninstall it? The world loads fine and the caves disappear until you reinstall. Anything built in a cave gets buried and will probably collapse.
Does it change my save or add files? No. Digs are stored where vanilla stores terrain edits.
Does it work with other terrain mods?
Searica's AdvancedTerrainModifiers and MoreTerrainTypes are supported. Mods that edit the heightmap should work. Mods
that replace terrain rendering or worldgen are untested. Run hearthbelow compat and paste it when you report a
conflict.
I painted my cave floor and it showed up on the surface.
Terrain paint is flat, so the cave floor and the ground above share it. Turn off Underground Painting if that
bothers you.