If a player rolls a six during the Miner Movement phase of his turn, he may choose to cave-in any tile by flipping it upside down. If a player rolls a one during Miner Movement, he may choose to revert any caved-in tile by flipping it back over.

If a player chooses to cave-in or revert a tile, he must forego Miner Movement. Otherwise, he may move up to the number rolled, as usual. Cave-ins may not take place when a player is rolling both dice to traverse a Secret Passage.

Tiles that are occupied by one or more Miners may not be caved-in. No tiles may be placed adjacent to caved-in tiles unless they were connected prior to the cave-in. When a caved-in tile is reverted, it must be placed in the original position, aligned with all adjacent paths.