Roof collapse

Roof collapse is a game event where roof that is too far away from any support structure is destroyed and damages anything in the same tile. The player receives an event notification when a roof tile collapses and the game is paused.

Structures like walls and columns can support roofing in a surrounding circular area with a diameter of 13 tiles. Roof tiles will collapse immediately once their last supporting structure is removed.

Effects

All roof collapses damage items and pawns in the same tile. They produce filth in the form of building and rock rubble. Constructed and thin roof will damage any items, furniture, or pawns in the same tile when they collapse.

Thick mountain roof will effectively destroy any items or pawns in the same tile when it collapses. Pawns are killed; their bodies, gear, and inventory are unrecoverable. Destroyed items leave no scrap parts.

Mountain roof is "un-removeable" because it cannot be designated for removal and also creates collapsed rocks when it should collapse. If the collapsed rock is mined out, mountain roof will collapse again indefinitely.

Analysis

The player can prevent roof collapse by premptively removing roof tiles at risk. Creating a Remove Roof zone on the necessary tiles will prompt a colonist to safely remove thin roof.

Roof collapse can also be manipulated into a weapon to damage entire rooms of enemies at once. Use frag grenades or any ranged weapon to destroy a pillar that was supporting roof over a killbox.