Combine 3 instead of 2 Mahjong tiles to remove them from the board. Normal mahjong rules apply for the free tiles. So either the left or right side of a Mahjong tile has to free and also the tile cannot be covered by another tile.
Triple Mahjong online games
Triple mahjong is another kind of mahjong game, the object of which is to remove all the tiles from the playing field. You need to remove three instead of two identical and not blocked knuckles from the construction, so be careful.