Our new Keys for the fire and Ice expansion to Terra Mystica. These keys are compatible with the second version of our Terra Mystica Overlays for the base game. Purchase of additional mat boards is unnecessary with the second version of our Base game overlays. This set contains four keys. Fire, Ice, Riverwalker and Shapeshifter. There is also an optional upgrade available for the Fire key. The upgraded key has cutouts to mark the terrain options with included terrain rings. Use the rings to mark either the most expensive, or cheapest terrain, whichever goes with your play style.