A casino (also known as a gambling house or a gaming establishment) is a place for certain types of gambling. The term is also used for a place that combines gambling with other leisure activities such as dining, entertainment, and shopping. Casinos are generally located near or combined with hotels, resorts, restaurants, retail shops, and other tourist attractions. Some casinos are also known for hosting live entertainment events such as stand-up comedy, concerts, and sports.

Casinos earn billions of dollars a year for their owners, investors, and Native American tribes. They attract millions of visitors from all over the world and generate huge revenues for the cities in which they are situated. Casinos are usually built on land or water and can range in size from massive resorts to small card rooms. Casino games include slot machines, keno, roulette, blackjack, craps, and poker.

In the twentieth century, casinos dramatically increased their use of technology to improve security. Video cameras now routinely monitor all the gambling areas; betting chips have built-in microcircuitry to track their movements and enable casinos to verify that all bets are placed correctly; and roulette wheels are electronically monitored to discover any statistical deviation from expected results.

Something about the nature of casino gambling seems to encourage cheating and theft, so casinos spend a lot of time and money on security. They also emphasize customer service by offering perks designed to encourage people to gamble more, like discounted travel packages, free buffets, and show tickets.