*A recently collapsed rock tile may not require as many actions to re-open, however an ore tile will likely require many hundred, or even thousand, actions to remove.
*Reinforcing a cave wall with a [[support beam]] will lower the chance of a cave-in on tiles surrounding that support. Once reinforced they may not be excavated, however a mayor may mine out the support should it reside on their deed. This would take approximately 50 actions just to remove the support.
'''A cave wall reinforced with a [[support beam]] off deed is literally impossible to remove. Please be mindful of this.''' Note that [[highway]]s are protected from cave-ins, thus tunnels for them dont require reinforcement.
*Ore veins are considered similar to reinforced walls for purposes of stability.
*The chance that a tile is replaced with a vein or shard other than rock is extremely low.