* You can raise clay tiles by dropping [[Pile of dirt|dirt]] or [[Heap of sand|sand]] on the corners.
* '''You can not lower clay tiles by digging. Be careful when dropping dirt, as raising a clay tile cannot be easily undone'''. If the northwest corner is adjacent to terraformable [[tile types]] that corner can be lowered through digging.
* Clay tiles can be lowered using the Level command, if all corners are higher or level to an adjacent flat tile. A digging skill of 70 is required to do this.
* Clay tiles can not be removed or changed to another type of tile.
* Dropping clay does not create clay tiles.