Domino, a type of tile game, is played with an arrangement of numbered dots or spots. Each domino has a specific number of spots on both its face and its border, which allows it to be distinguished from other dominoes. Like playing cards, of which they are a variant, each domino bears identifying marks on one side and is blank or identically patterned on the other side. Unlike cards, however, dominoes are marked with an arrangement of spots, or “pips,” similar to those used on a die, except that some squares are blank (indicated in the listing below by a zero).
Like any chain reaction, the fall of a domino begins when a single unit topples another. Once the first domino falls, its adjacent tiles will be triggered to fall by an electromagnetic force called gravitational inertia. This force, which is the same as that which pulls on the earth and causes it to rotate, is independent of the size of the triggering domino. The resulting chain of reactions can continue until all the available dominoes have been toppled.
As the chain of dominoes grows longer, the players must position themselves to take advantage of the accumulating points or scores. The person to the right of the leader may play a domino in order to build up his score, or can pass it to the left, depending on the rules of the particular game being played. Once the players have determined their seating arrangements, they draw a domino from the stock, or boneyard, which must match the value of the preceding tile to be played. In most games, a double is played crosswise, while a single is played lengthwise.
After a player has drawn his tiles, he places them down on the table in a line, or string, of dominoes that is called a layout or a string. This configuration is then followed by the players in turn, who must position their dominoes so that they can be joined to the previous domino with a matching number on both ends of the line of play. A player is said to “stitch up” the ends of a domino, if upon a previous play there is an open end on the side that matches his own tile.
When a winning hand is made, the losing players count the total number of pips on the ends of their remaining dominoes. The winner takes the total as his score. If a game has tie scoring, the tied players may agree to a rule variation that counts only one end of a domino, rather than counting both ends as equal in value. This is often referred to as byeing. This is a common method for breaking ties. This is also a commonly used scoring method in partnership games. Alternatively, the players may each draw a number of additional dominoes from the stock and add them to their hands, depending on the rules of the particular game.