A domino is a small tile with a line down the middle and each end showing a number. The most common set has 28 unique tiles, each with either a 0 (blank) or a 1 on one end and a 3 or 5 on the other. Dominoes are usually played on a tabletop with the pieces standing on their edge and can be made from a wide variety of materials. Some are even made from glass or ceramic clay.
Traditionally, dominoes were made of bone or silver lip ocean pearl oyster shell (mother of pearl), ivory, or a dark hardwood such as ebony, with contrasting black or white pips inlaid or painted on each. The dominoes were then glued together to form the finished set. More recently, sets have been made from a variety of natural materials including stone (e.g., marble or granite); woods such as ebony or ash; metals (e.g., brass or pewter); and even frosted glass or crystal. Such sets often have a more novel look and are heavier than those made of polymer, but they also tend to be more expensive.
A number of games can be played with a domino set, but they are most commonly used for positional play. This type of game involves positioning the dominoes so that their ends show a combination of numbers which are useful to the player or which form some specified total. The players then take turns playing these dominoes onto the table so that the resulting chain of dominoes grows in length. Normally the chain must reach a point at which all the players can play a domino but, if the chain becomes stuck, one or more players may “knock” or rap the table and pass their turn.
Some people use the art of domino design to create stunning structures in which the dominoes fall according to the laws of physics. Such structures can be anything from straight or curved lines to grids that form pictures when they fall, or 3-D structures such as towers or pyramids. The most important thing to remember is to plan carefully, and test each section of an installation before adding it to the final piece.
Hevesh, a domino artist who has created installations for movies, TV shows, and events, including an album launch for Katy Perry, says that one physical phenomenon is especially crucial for her work: gravity. This force pulls each knocked-over domino toward Earth and carries it into contact with the next domino, setting off the chain reaction. She carefully tests each part of a design before filming it in slow motion, and makes adjustments to ensure that it works.
As the popularity of dominoes has increased in recent years, many people have taken up the hobby of making their own sets. Detailed instructions have been published for a variety of different styles and designs. The most popular are the simple, single-line setups, but more elaborate arrangements are possible. One domino artist has a YouTube channel with more than 2 million subscribers in which she displays some of her creations.