A casino is a gambling establishment with a variety of gambling games and entertainment. It is often combined with hotels, restaurants, retail shops, cruise ships, and other tourist attractions. In many countries, casinos are licensed and regulated by the government. Casinos use a variety of technologies to ensure security and fairness. Some examples are cameras that monitor betting patterns in table games to detect any anomaly; electronic systems that supervise each bet placed minute by minute and warn dealers of any irregularity; and roulette wheels that are electronically monitored to discover any statistical deviation from their expected results.

While some casino games involve a high degree of luck, most have mathematically determined odds that ensure the house always has an advantage over the players, also known as the house edge or expected value. The advantage of the house may be a small percentage, or a large amount. It is important to the casino that it knows both of these numbers, and how they fluctuate over time (known as variance), so it can plan its resources appropriately. Mathematicians who specialize in these tasks are called gaming mathematicians and analysts.

Casinos have become a global phenomenon, and they are now found in most countries around the world. In America, the first legal casinos were opened in Atlantic City and New Jersey, but they spread rapidly across the country. In the 1980s and ’90s, many states amended their antigambling laws to permit casinos. A number of American Indian reservations have casinos as well.