A casino (from Italian: casin) is a building or room equipped with gambling devices, such as slot machines and poker tables. It is also a facility for entertainment, including shows and dining. Casinos are regulated and licensed by governments to ensure honesty and integrity. They are also heavily guarded to prevent criminal activity. The classic example is the casino at Monte Carlo, which has been a major source of revenue for the principality of Monaco since 1863.

Modern casino security is usually divided between a physical security force and a specialized surveillance department. The former patrols the premises and responds to calls for assistance or reports of suspicious or definite criminal activity; the latter operates the casino’s closed circuit television system, a key component of its overall security operations. Casinos have also incorporated new technology into their operations to enhance gaming security and improve game results. For instance, chip tracking systems monitor betting amounts minute by minute and warn dealers of any anomalies; roulette wheels are electronically monitored to detect and quickly discover deviations from expected results.

Although the majority of states prohibit casino gambling, a few allow it in some form. These include Atlantic City, New Jersey; Detroit, Michigan; Las Vegas, Nevada; and Biloxi, Mississippi. In addition, many American Indian reservations have casinos on their land. Moreover, some states offer legalized online gambling. The state of Hawaii and Utah, however, make all forms of gambling illegal. In general, casino winnings are considered taxable income.