About 51 million people a year visit casinos in the United States. That’s the equivalent of a quarter of the American population over 21. From the glittering Las Vegas strip to the illegal pai gow parlors of New York’s Chinatown, they choose from more than 3,000 gambling establishments.

What makes one casino stand out from another is not the number of slot machines or the number of tables, but rather the amenities that are offered to attract and pamper high-stakes gamblers. From luxurious rooms to opulent dining and spa services, the best casinos offer a wide variety of gambling options to satisfy any taste.

As a business, a casino has to make sure its profits match the amount of money invested. That’s why there is no such thing as a “free casino,” and why so much time, effort and money is spent on security.

While most casino games are based on chance, the odds are that you will lose more than you win. Even if you play perfectly, the house edge will eventually catch up to you. Casinos spend enormous sums to prevent this from happening, so the layout of every room, the way table games are positioned and the expected reactions and motions of patrons all follow certain patterns that make it easier for security personnel to spot cheating or a mistake.

In addition, the comps that a casino offers to its big players (room discounts, free meals and tickets to shows) are often monitored with sophisticated cameras and analyzed by computer. This ‘eye in the sky’ allows security to see exactly what’s going on and can be adjusted quickly by operators when the action changes.