A casino, or gambling den, is a place where people can gamble on games of chance. While gambling has existed for thousands of years, casinos as we know them did not appear until the late 19th century. They are usually large, elaborately decorated buildings that feature a variety of gambling games. They are a major source of revenue for many cities and states.

Most modern casinos offer a wide range of casino games, including roulette, baccarat, craps, blackjack and video poker. Most of these games have mathematically determined odds that give the house a consistent advantage over players, which is known as the house edge. In games such as poker where players compete against each other, the casino takes a percentage of the pot, which is called the rake. Some casinos also provide complimentary items or services to certain patrons, known as comps.

Security is a key concern for casino owners. In addition to cameras, they employ other technology to ensure that their clients are not cheating or stealing. For example, some table games have betting chips with built-in microcircuitry that communicate with computer systems to monitor the amount of money wagered minute by minute, and to detect any statistical deviation from expectations. Roulette wheels are electronically monitored to discover any tampering; and casino staff watch each other’s actions to spot any suspicious behavior.

Gambling has a long history, with primitive protodice and carved six-sided dice found at the oldest archaeological sites. It took a while for the idea to take hold, however, and it was not until the 16th century that small private clubs, called ridotti, appeared in Italy. These were often owned by organized crime figures, who had lots of money to invest and no problems with gambling’s seamy image. In Nevada, mob money flowed into casinos until federal crackdowns and the threat of losing a casino license meant that legitimate businessmen had to step in to buy out the mobsters and take over.