Mahjong online (Mahjongg, Mahjong Solitaire, or Shanghai Solitaire) uses 144 tiles. When you start the game, these tiles are placed in a four-player pattern. You can’t see tiles hidden beneath other tiles. You must remove the upper tiles and expose the tiles underneath.

You can only match two identical free tiles. A free tile is the one that is uncovered and unblocked on its left or right sides. Once you remove all pairs of tiles from the board, you win the game.

Many tiles look similar, but they have slight differences. So you need to have a sharp mind and concentrate on the differences to find identical tiles.