Rock



When players picks a gem on their turn, the other four gems are replaced by rocks.

Game mechanics of rocks
Rocks are impassable by land units. They also block the laying down of new gems, with error message given for it.

Rocks can be removed by selecting them and then either clicking "remove gem" or pressing R key on the keyboard. Multiple rocks can be selected by holding down Shift key when clicking.

Use of Rocks
As they're impassable by dwarfs, rocks are integral in building a maze.

Furthermore, as they do not damage enemy units they're useful in concentrating fire near the path and guiding kills to gems.