From the glittering Las Vegas strip to illegal pai gow parlors in New York’s Chinatown, casinos attract millions of people every year. Many of them are tourists, who take bus trips or flights to gamble and play casino games. Others are locals, who visit casinos to socialize with friends and family or to watch the many floor shows. Regardless of their location, these casinos must have enough money to keep the doors open and the lights on.

Gambling in its many forms has been part of human culture for millennia, with evidence dating back to 2300 BC China and later to Roman times, when the first dice and playing cards appeared. The modern casino carries on this tradition, with gamblers placing bets at tables and slot machines. These bets are based on the chance that a particular number or combination will appear and have certain mathematical odds. The house always has a slight advantage over the players, known as the house edge.

Casinos must focus on customer service in order to survive, and they often give away free goods and services to frequent patrons, or “comps.” These perks range from food and beverage credits to hotel rooms and show tickets. The best comps are for the big spenders, and some casinos even offer limo service and airline tickets for those who spend lots of time at the gaming tables. The most popular casino game is slot machines, followed by baccarat and table poker.