Mahjong Objetive: The goal is to clear the board by removing all the matching identical pairs from the layout. A valid pair consists of two tiles which are both free and identical. In more details, you can remove a pair of tiles if the following condition are true: The tiles are identical (e.g. 4 and 4, I and I, etc.) Each tile of the pair must comply with the following rules: -No other tile is lying above or is partially covering it. -No other tile is lying to the left or to the right of it.