A casino is a gambling establishment offering a variety of games, such as blackjack, roulette and poker. Many casinos also offer entertainment such as shows and fine dining. Some are combined with hotels, resorts or cruise ships. Others are stand-alone. Some states legalize gambling while others outlaw it or limit it to tribal land.

Casinos profit by taking a small percentage of all bets made in their establishments, a sum known as the house edge. This advantage is built into every game offered by a casino and can be as low as two percent, but over time it adds up to enough money for casinos to build elaborate hotels, fountains, towers and replicas of famous landmarks.

Something about gambling (perhaps the presence of large amounts of money) seems to encourage cheating and stealing, and casinos spend a great deal of effort and money on security. Casinos employ guards, some of whom wear bulletproof vests, and they use technology to monitor their patrons as well. For example, betting chips have built-in microcircuitry to allow casinos to oversee the exact amount wagered minute by minute and to detect any suspicious pattern; and roulette wheels are electronically monitored regularly to spot statistical deviations.

Although gamblers have been around for millennia, the modern casino began to appear in Europe in the second half of the 19th century. The first one was opened in Monte Carlo in 1863, and casinos have become a major source of income for the principality ever since. In the United States, legalized casinos are a popular destination for out-of-town visitors, but they also generate a substantial local economic boost. Critics point out, however, that compulsive gambling undermines family life, causes people to quit their jobs and hurts property values in the surrounding area.