Setup
Place all the tiles flat on the table face down and mix them in a random fashion to set up the game. This collection of unplayed tiles is known as the "boneyard."
Drawing Tiles
The number of tiles each player draws from the boneyard depends upon the number of players. In a 2-person game, each player draws 7 tiles. For a 3- or 4-person game, each player draws 5 tiles. All players then hide their tiles from each other.
First Play
The player with the tile displaying the highest double numbers places it on the table to start the game. If none of the players has a tile with double numbers, each player adds up the number of dots on all of their tiles, and the player with the highest total number plays first.
Game Play
Play proceeds to the left, which each player adding a domino to the board by matching a number on one of his tiles to an unused (open ended) tile that has been played. If he cannot play, he must draw from the boneyard until he can, or until the boneyard is empty and he must pass. Note that tiles with double numbers are played on the end of an already-played tile, with the middle line centered on the end of the tile.
Ending Play
Play ends when one player has used all her tiles, or when all players must pass because no one can make a valid play. In this case, the player with the least number of dots on his remaining dominoes wins that round.
Scoring
The winning player of the round receives one point for each dot (or "pip") on all the other players&' tiles. She then must subtract one point for each dot on her own tiles--if any.
Winning
Basic ("draw") dominoes is generally played to 100 points, with the first player to reach 100 declared the winner. Some players like to use a cribbage board for scoring, playing to a final score of 121. Most prefer to keep score using pencil and paper.