A casino is an entertainment establishment featuring games of chance. Most casinos feature a variety of slot machines, blackjack tables and other table games. Some casinos also offer video poker and other electronic gaming devices. The precise origin of gambling is not known, but it is believed that in most societies, some form of game of chance has been played. Modern casino gambling first took root in the United States in the early twentieth century, with the opening of the first commercial casinos in Atlantic City and on American Indian reservations, which are not subject to state antigambling statutes.
While legitimate businessmen were initially reluctant to get involved with casinos, which carried the taint of mob involvement due to their illegal nature, organized crime figures had plenty of cash from their drug dealing, extortion and other rackets to fund them. The mobsters were soon joined by wealthy real estate investors and hotel chains, who realized the potential profits from gambling destinations. These businesses bought out the mobsters and began running their casinos independently, and mob control was gradually phased out.
Most casinos accept bets only within established limits and are based on mathematical odds that always give the house a negative expectation (house edge). Some games, such as poker, allow players to compete against each other, in which case the casino takes a cut of the money bet by the players, called the rake. Most casino games require minimal skill, making them popular with casual players and beginners. Some casino games require more skill or strategy, such as blackjack and roulette, and are therefore more popular among seasoned gamblers.