A casino (also called a gaming house or a gambling house) is an establishment for certain types of gambling. Casinos are also known for hosting live entertainment events such as stand-up comedy, concerts, and sports. In some countries, casinos are licensed and regulated by the government. In other countries, they are unlicensed and operate informally. Casinos are commonly found in cities with a large tourist industry, such as Las Vegas and Atlantic City, and on American Indian reservations.

Aside from their primary purpose, casinos often serve to stimulate local economies. They offer jobs to a significant number of people, both directly and through contractors and vendors, and generate tax revenue for the host community. This money may then be used to improve other aspects of the local economy, such as education, public services, and infrastructure.

Gambling has been around for many centuries in different forms. The exact origin of gambling is uncertain, but it is believed that it developed from the use of dice in China in the 7th century AD. In the modern sense of the word, the first casinos appeared in Atlantic City and Las Vegas in the United States, and then spread to other locations, including American Indian reservations not subject to state antigambling laws.

Casinos rely on mathematical probabilities to calculate expected profit and loss, as well as variance (the standard deviation of profits or losses). These calculations are performed by gaming mathematicians and computer programmers who specialize in the field. Players must also make decisions based on these probabilities and odds, which improves their analytical thinking and problem-solving skills.