A domino is a gaming piece (usually a rectangular tile) that is marked with a pattern of dots, similar to those on dice, but blank or identically patterned on the other side. Like playing cards and dice, dominoes are used to play a wide variety of games. Some examples are straight lines that run across the table, curved lines or grids that form pictures when they fall, or even 3D structures such as towers and pyramids. In addition to being entertainment, dominoes also provide a good way to practice simple engineering and design skills.
There are many different games played with dominoes, and the rules vary between them. In most cases, a set of dominoes is shuffled and the players draw tiles for their hands. The player who draws the heaviest domino will make the first play of the game. If there is a tie, the tie may be broken by drawing extra dominoes from the stock, or a number of other ways that vary according to the rules of the particular game being played.
After a player has drawn his hand, the remaining tiles are placed face down in a line on the table, called the stock or boneyard. This is done so that the players can see their own tiles, but not the value of their opponents’ tiles. The heaviest tile is typically the first to be played, although some games specify that the player must play a double. A player may also purchase additional tiles from the stock as described in the section below, Buying and Passing Tiles.
The way that the dominoes are then arranged on the table determines how the game is played. Generally, a chain of tiles is built up by each player placing a tile edge to edge against another so that the two matching ends touch fully, with a domino played to a double touching only one of its edges (the other is considered the “open end”). The shape of the chain develops snake-line as the chains grow in length and complexity.
The energy that is in the open end of a domino, when it is played on top of a previous tile and it then falls over, converts to kinetic energy (the energy of motion), and that kinetic energy spreads from one domino to the next until all the tiles are pushed over. This process is known as the Domino Effect. This principle is also demonstrated in physics demonstrations, whereby a small domino knocked over a larger stack of them. It is a common misconception that this type of event cannot be repeated, but in fact, the same principles apply. In the video below, University of British Columbia physicist Lorne Whitehead sets up 13 dominoes to demonstrate this phenomenon, which can be replicated in the lab. The video is well worth a watch, and will give you a glimpse into some of the amazing power of the Domino Effect.