An attempt to mitigate the 'all or nothing' affect of biters breaching your walls. Biters which damage a structure will take damage in return. This means that if they breach your walls that they will eventually all die off.
Mods introducing new content into the game.
An attempt to mitigate the 'all or nothing' affect of biters breaching your walls. Biters which damage a structure will take damage in return. This means that if they breach your walls that they will eventually all die off.