Quads is a game similar in looks to dominoes but far different in play.Each players draws four stones from a pool of 36 known as the Quarry. Each stone has a central 'point value' number and each of the four outside edges has a number from 1 - 6.Players must match outside numbers with stones already played to add up to the central point value number on the tile being played.Points scored are multiplied by the number of sides the player is able to match up when a stone is placed.After placing a stone a new one is drawn from the Quarry until the Quarry is empty. Players then play until all 36 stones have been played. Players only play one stone per turn.The new version of this game called Quartile has 49 tiles. - BoardGameGeek