A casino, also known as a gambling house or a gaming establishment, is a place where people can gamble. Most casinos are built near or combined with hotels, restaurants, retail shops, and other tourist attractions. In the United States, there are over 1,000 casinos, with Las Vegas having the largest concentration.

The games in a casino generally involve chance, with some involving skill. In most cases, the odds are mathematically determined to ensure that the casino has a profit over the players, which is called the house edge. In games that require skill, the advantage is more variable and depends on the rules of the game, the number of cards dealt, the skill level of the player, and the amount of money bet. In some games, the house also takes a commission from each bet, known as the rake.

Casinos use a variety of security measures, including video surveillance. Some have catwalks in the ceiling above the gaming floor that allow security personnel to look down on the activities below, through one-way glass. Casinos are also wired for electronic surveillance, with every slot machine in a given casino electronically monitored minute-by-minute to discover any statistical deviations from expected results. In some modern casinos, betting chips with microcircuitry interact with computer systems to oversee the exact amounts wagered on a minute-by-minute basis. This technology is often used for general security, but is increasingly being used to monitor the actual games as well.