Domino is a small rectangular block, either wooden or plastic, that has blank or marked faces that resemble those of dice. It is used to play a variety of games, both competitive and cooperative. It can also be arranged to make art in the form of straight lines, curved lines, grids that form pictures, or 3D structures such as towers and pyramids. Domino is a common toy for children, and some adults use it for puzzles and as tools for teaching mathematics. It is the inspiration for the expression “a domino effect,” which describes a chain reaction that starts with one simple event and leads to greater-and sometimes catastrophic-consequences.
In Domino, players make their moves in a line that is called the layout, string, or line of play. The first domino played is known as the setter, downer, or lead. Each subsequent player adds to the line of play by putting his or her own tile down on top of another domino.
When a domino is played, it creates an electric pulse that travels down the line, just like a nerve impulse in the body. This pulse is able to move quickly, even if the next domino is not yet in place, and is only disrupted by other factors such as obstacles or an opponent’s action.
Most commonly, a domino is made of wood, although sets have been manufactured from many different materials including stone (e.g., marble or granite); other types of natural woods; metals (e.g., brass or pewter); ceramic clay; and other polymer materials. There are also sets made from more luxurious materials such as bone, silver lip ocean pearl oyster shell (mother of pearl), ivory, or a dark hardwood such as ebony with contrasting black or white pips.
Once a set of dominoes has been shuffled and each player has drawn his or her own hand, it is possible that there will be a surplus of tiles left in the stock. These are sometimes known as passing or byeing, depending on the game being played. In these cases, the player draws a number of tiles from the stock that are permitted under the rules of the game, and adds them to his or her hand.
After the players have completed their hands, it is determined who will make the first play. This is usually based on the heaviest tile in the hand, but other criteria may be used. The player who makes the first play is often referred to as the setter, downer, or leader, and he or she will put his or her tile face up on the table. The other players then take turns playing their pieces on top of the first. Play continues until a player cannot continue, or chips out, according to the rules of the particular game being played. If this happens, the remaining players share the winnings.