A casino is a gambling establishment. A number of countries have legalized casinos, with the United States leading the world in both the number of licensed casinos and casino hotels. Casinos are generally located in areas that are highly visible to the public and often include a hotel, restaurant, and bar. Many casinos provide gambling and entertainment, including live music and dancing. Some casinos specialize in certain games, such as poker or sports betting.

The word casino is a diminutive form of the Italian casin, meaning “little house.” The OED lists four definitions for the noun, but none are obsolete. The earliest evidence for the noun dates from the early 1700s.

In most casino games, patrons bet against the house rather than against other players. Casinos earn money by taking a percentage of total wagers made, known as the vig or edge. This is a significant component of the overall income of a casino, and it is very rare for an individual to win more than the house can afford to pay out, even on a single day.

Most casino games are based on chance, but some require skill. The best known of these are blackjack and roulette, which allow players to modify their bets based on the odds of winning or losing. In addition to the traditional table games, casinos also offer electronic gaming machines and, since the 1980s, video poker machines. In the United States, slot machines and video poker account for a majority of casino income.