Players in turn lay tiles onto the open ends of the domino layout with same-number adjacent to same-number (further doubles are placed horizontally onto the ends of the layout but are not played to allow play to branch four ways). Should a player be unable to set a domino from their hand onto the layout, they must continue drawing tiles from the boneyard until they are able to play one or the boneyard is exhausted.
Players score points whenever they play a tile with its open end bearing the same suit as one or more other open ends of the layout. The number of points scored is as follows:
Players score one point for each end of the layout bearing the same open suit. However, whenever any double is on the end of the layout with one or more open ends bearing the same suit, then the double scores two points in addition to the points for the other single suits open. Because there are four open ends on the layout, it is possible to have one or two suits with another tile of the same suit on the open ends of the layout, and players score for both matching suits whenever there are two. A player doesn't have to play a tile with a matching open end to score points, he may score the points for any open ends already bearing the same suit after he has played a tile. This means that the lead player who sets down the first double automatically scores two points as well as the subsequent players who play a tile until the initially set double is played on all four sides. The highest possible number of points scored in a turn would be six when there are two doubles with a matching single on the open ends.
Once a player has dominoed by setting their last tile, or the game is blocked with no player able to set a tile, the round is over and the player who dominoed or has the lowest total of pips left in their hand, is the winner of that round. The winner of a round then scores 1 point in addition to their already scored points made during play.
The lead passes to the next player in turn for each subsequent round. A number of rounds are played and the first player to score 100 points, wins the game.
Sometimes played with the last two tiles remaining in the boneyard not drawn when players can't make a play.