Domino is a game of skill and strategy using a set of small rectangular blocks marked with pips resembling those on dice. It may be played by two or more players. A domino has a number of sides; each side can be used to make a single move, or one domino can be laid on top of another and played from both ends. The most common set is made of twenty-eight pieces, although many games have variations that use fewer or more. Some have specific rules that only apply to that game; others have universal rules that all games follow.
We’ve all seen those amazing domino constructions, a line of hundreds or even thousands of pieces set up in a straight or curved row and then, with the flick of one, falling in a cascade of rhythmic motion. They’re impressive to watch, but it’s what happens behind the scenes that really makes them work. Dominoes set up in careful sequence, each one triggering the next, just like a firing neuron in the brain.
Physicist Stephen Morris says a key ingredient to a great domino setup is the force of gravity. When a domino is stood upright against this force, it stores energy based on its position. As the domino falls, that energy is converted from potential to kinetic energy and creates the chain reaction of subsequent dominoes falling.
A player begins play by drawing a domino from the stock, which is the remaining unplayed tiles in the hand of each player. The first player to play a tile is determined by the rules of the particular game being played. This player is known as the “setter,” the “downer,” or the “lead.” The first tile played must be a double and must touch the end of any other already in play. If a double is played without touching an end, the player who plays it is said to have “stitched up” the ends.
After the initial draw, each player may purchase tiles from the stock (again according to the rules of the game). This can break ties or prevent an undesired domino from being played first. A player can also choose to pass a turn, which means they don’t buy any tiles and neither do the other players for that turn.
When the heaviest domino is drawn, the player may open the game by playing this domino as the first move. The player may also be able to purchase additional tiles from the stock if they are available. The next player to play a tile in the same manner becomes the new lead and makes the following move.