A casino is a place where people can gamble. It is often combined with hotels, resorts, restaurants, retail shops and other tourist attractions. Some casinos host live entertainment, such as stand-up comedy, concerts and sports events.

While glitzy musical shows, lighted fountains and theme hotels lure visitors, most casinos exist because of gambling: slots, blackjack, poker, roulette, craps, baccarat and more provide the billions in profits that draw crowds. While a few states have legalized casinos, many more ban them or limit their growth. Regardless of the law, some casinos still thrive.

In the United States, casinos are most famous in Nevada and Atlantic City. Las Vegas alone is home to more than 340 casinos. Other big cities, such as Chicago, also have large casinos. Casinos are a major source of revenue for many cities and counties, but they are not always popular with residents.

Although gambling probably predates written history, the modern casino is a relatively recent invention. The first large casinos were built in the sixteenth century during a gambling craze that swept Europe. Italian aristocrats would gather at private clubs known as ridotti to gamble and socialize, even though the activity was technically illegal.

Casinos have a reputation for offering comps, or complimentary items, to players. These perks can include free hotel rooms, food and show tickets. In the past, these were offered to high rollers who placed large bets and spent hours playing games. Nowadays, casinos use electronic monitoring systems and sophisticated software to prevent cheating by patrons and staff. For example, betting chips with built-in microcircuitry allow casinos to oversee amounts wagered minute by minute and warn staff of any anomalies; roulette wheels are regularly electronically monitored for statistical deviations.