Domino is the name of a game and a building material, but it is also a term that describes the domino effect, the phenomenon in which one small action causes much bigger events to occur. People have been using dominoes to create intricate designs for centuries, but the most famous example of the effect happened in 1989. On that day, a teenager in the U.S. tripped over a domino in his driveway, knocking it over and starting a chain reaction that eventually led to the collapse of the Twin Towers of the World Trade Center.

Children often play with dominoes, stacking them on end in long lines. When the first domino is tipped over, it sets off a chain reaction, causing the next tile to tip and so on until all of the dominoes fall over. This simple game teaches kids how to follow a sequence and create patterns with their hands. It is also the inspiration for a popular phrase: “The domino effect.”

When Lily Hevesh was 9, her grandparents gave her a classic 28-piece set of dominoes. She loved setting them up in straight and curved lines, flicking the first one and watching them all fall. Her fascination with the game has grown into a career, and she now creates spectacular domino installations for movies, TV shows and even live events like the Katy Perry album launch. She also posts videos of her creations on YouTube.

Hevesh says the key to her success is physics. A domino is upright because it’s being supported by gravity, and each time a player moves the domino from its position, it’s releasing energy that can be converted to kinetic energy when it falls over. This energy is what causes the next domino in the line to tumble, and it starts a domino effect that can lead to an amazing show of physics.

There are many different kinds of domino games, but most involve blocking or scoring. The most common domino sets contain either double six or double nine tiles, but larger ones are available. Some sets have numbers on both sides of the domino, while others use Arabic numerals to make the numbering more readable.

Many domino games can be played by two players, but some require more than four. To accommodate these, the dominoes are extended by adding more pips on each end. This increases the total number of possible combinations and adds new end values such as zero and blank. The most common extension is to the double-twelve (91 tiles) and double-nine (55 tiles) domino sets.

Another variation on the block and draw game involves placing sleeping dominoes between the standing dominoes. The rules are similar, but each player takes fewer dominoes to start with: two players begin with 7 dominoes, three players start with 5 tiles and five players start with 3 tiles. If a player cannot place a domino, they pass their turn and wait until the sleeping dominoes are used up. Then they can choose one to take the spot and continue the chain.