Domino is a set of flat, thumb-sized blocks that can be laid down in lines or curved shapes. Each domino has two ends that may bear either zero or a number of spots or dots, from one to six, in the most common variant (known as a double-six set). A domino is also sometimes called a bone, card, or piece. It is usually twice as long as it is wide, with a central line to divide it visually into squares. Each square has a value, which may be referred to as its rank or weight; the more spots or dots on a domino, the higher its rank.

The first domino in a line or pattern of dominoes falls when there is enough force to tip it past its point of inertia. A domino’s bottom then slips against the next domino, creating friction that converts some of the energy of its movement into heat and sound. The process continues, with each domino pushing on the next until they all fall over. The domino effect is a simple yet powerful principle that applies to many aspects of life.

Lily Hevesh started collecting dominoes at age 9, and she’s been creating impressive domino setups ever since. Her YouTube channel, Hevesh5, has more than 2 million subscribers. When she’s working on a new project, she tests each section of the arrangement to make sure it works as intended.

She’s often asked how she has the time to do so much. “I wake up every morning at 5 a.m. and make my bed,” she says. “That small victory right after getting out of bed drastically increases my chances of a productive day.” This is one example of what she calls domino actions: high leverage actions that trigger a chain reaction.

A domino is the simplest form of a set, but other types of sets have been used in games. In general, these can be divided into blocking and scoring games. Blocking games are played by laying dominoes edge to edge against each other until one’s hand is empty and blocking the opponent’s, while scoring games are generally adaptations of card games that were once popular in some areas to circumvent religious proscriptions against playing cards.

Most dominoes are made from wood, but they have been manufactured from many other materials including stone (such as marble, granite or soapstone); metals (e.g., brass or pewter); ceramic clay; and other natural materials like bone, silver lip ocean pearl oyster shell (mother of pearl or ivory), or ebony. Contemporary sets are also often made of plastics.

In addition to pizza-delivery vehicles, Domino’s is also experimenting with delivery by drones and robots. While these are primarily designed to save money on labor costs, they could eventually be used to augment the company’s existing delivery service. Nevertheless, the company’s main goal is to make it as convenient as possible for people to order and receive their food. In some locations, the Domino’s app lets customers order by texting an emoji or using Amazon Echo devices.