A tile-laying and -stacking game, a basic set consists of 40 hexagonal tiles worth different numbers of points. The tile are ridged so that three tiles together can form a base for a fourth tile to sit upon them.Gameplay consists of playing tiles from a 'hand' of three tiles. Tiles laid on top of other tiles are required to have the same pattern inscribed on them as the tile making up their base. Tiles placed above the first level score depending on the point value of the tile played and the level it was played on .Sets come in a single color, and different sets come in different colors, allowing for expansion and more advanced play in which color also becomes a factor for scoring. - BoardGameGeek