I'm wondering if 7 Days would benefit from a selectable water table, that would cause underground lairs to flood without a pump to hold back the water... Everyone seems to go subsurface for the most part, and the size of the facilities would require air and water pumps to keep them habitable. Which would require generators... Which would require fuel... And ventilation. And maintenance.
7 days to die, not 7 days to dig...
7 days to die, not 7 days to dig...