A casino, also known as a gambling house or a gaming establishment, is a place where people can play various games of chance for money. Most casinos offer a variety of gaming options, including slot machines, table games, and poker. Some are combined with hotels, restaurants, and retail shopping. Others focus on providing live entertainment, such as comedy shows and concerts. Casinos are often located in or near cities and serve as a tourist attraction.

A modern casino is a sophisticated, themed structure with high-tech amenities and a wide array of betting options. But despite all the fancy extras, the vast majority of the profits that casinos rake in come from games of chance—and a bit of skill—such as blackjack, roulette, and baccarat.

The MGM Grand in Las Vegas is a storied gambler’s den that attracts hardened dollar spinners and curious novices alike. In addition to its usual range of table and slot games, the Grand offers a lively area for sports betting.

But, as in any other business, a casino’s bottom line comes down to the house edge, or its built-in profit margin. The house edge is the mathematically determined average advantage that the house has over the players in any given game, and it applies to all games of chance (and some games of skill).

While a casino may add other attractions to appeal to tourists—such as musical shows, lighted fountains, and elaborate themes—the vast majority of its profits still come from gambling. Slot machines, craps, keno, roulette, and blackjack are just some of the many games that bring in billions of dollars for U.S. casinos each year.

Casinos have been around for hundreds of years, but they really took off in the 1950s when Nevada legalized gambling and other states followed suit. As organized crime figures accumulated more cash from drug dealing, extortion, and other illegal rackets, they began investing in casinos to capitalize on the growing market for legal gambling. In the past, mob-owned casinos had a tainted reputation, but federal crackdowns and the threat of losing a license at the slightest hint of Mafia involvement now keep mobster money out of casino operations.

Besides cameras, casinos employ a variety of other security measures to ensure the safety and integrity of their customers. For example, the routines and patterns of casino games make it easier for security personnel to spot suspicious behavior. And, in some cases, the rules of the game require players to act a certain way—for instance, keeping their cards visible at all times.