Mahjong Solitaire is a single-player matching game that uses a set of Mahjong tiles rather than cards.
Tiles are arranged in a special pattern of several layers with their faces upwards. A tile is said to be open or exposed if it can be moved either left or right without disturbing other tiles. The goal is to match open pairs of identical tiles and remove them from the board, possibly exposing the tiles under them for play. The game is finished when all pairs of tiles have been removed from the board.
Tiles that are below other tiles cannot be seen. Sometimes, tiles are only partially covered by other tiles, and the extent to which such tiles can be distinguished depends on the actual tile set.