A casino, or gaming establishment, is a place where people can gamble by playing games of chance or skill. These games may include poker, blackjack, roulette, and craps. Some casinos also offer sports betting and horse racing. Some are built as huge resorts, while others are small card rooms in bars or restaurants. Some states have legalized gambling, allowing the operation of casinos on land or water. Others have prohibited it or regulated it.

While gambling likely predates recorded history, the modern casino as a place to find a variety of different ways to gamble under one roof did not emerge until the 16th century, when a gambling craze took hold in Europe. It spread to America as the century progressed, with many Native American tribes taking advantage of the opportunity to open casinos in their areas.

Casinos earn billions of dollars each year for the companies, investors, and Native American tribes that own and operate them. They also provide jobs and generate tax revenue in the cities, states, and countries where they are located. Many casinos offer luxurious accommodations and other entertainment, including stage shows, food, drinks, and shopping.

Casinos are designed to maximize the number of visitors and their spending. They make money by offering comps, or complimentary items, to high-spending patrons. These perks are often free spectacular entertainment, reduced-fare transportation, hotel rooms, and meals. Casinos also monitor the odds of the games, and use technology to detect cheating. For example, poker tables have special chips with microcircuitry that interact with electronic systems to record the exact amounts wagered minute-by-minute and warn the players when a bet is suspicious; roulette wheels are regularly monitored electronically to discover any statistical deviation from their expected value.