How Casinos Work

Casino Games

A blackjack game
A blackjack game
Public Domain

­A wide variety of games can be found at casinos, and some casinos seem to specialize in inventing new games to draw more players. In some places, the games that are allowed are regulated by state laws. This section will cover the most common casino games.


Blackjack is one of the easiest table games. The object is to get a hand of cards whose values are as close to 21 as possible without going over (busting). Only the values of the cards are considered, not the suit -- picture cards are worth ten, and an Ace can be worth 11 or one, whichever is more advantageous to the player. The house advantage can be minimized by using a strategy or even counting cards, but if a casino suspects card counting, they can throw you out. The house edge without counting is about two percent. For more details, see How Blackjack Works.

Slot Machines

Slot machines are the most popular casino games, and casinos earn a larger proportion of their money from them than any other game [Source: PBS]. Part of the slot machine's appeal is the simplicity -- the player puts in some money, pulls a handle or pushes a button and waits to see the outcome. No amount of player skill or strategy can affect the outcome in any way. Varying bands of colored shapes roll on reels (actual physical reels or a video representation of them). If the right pattern comes up, the player wins a predetermined amount of money. Slot machines used to be mechanical devices with reels of the shapes spinning past, but today all slot machines are controlled by on-board computer chips. There are still slots with actual reels, but they are computer-controlled as well. Modern slot machines come in a dizzying array of colors and themes.

Slot machines in Las Vegas. Slot machines in Las Vegas.
Slot machines in Las Vegas.
Public Domain

Most states have laws regulating the minimum payout frequency of a slot machine, usually about 75 percent. In other words, the house edge is a whopping 25 percent. However, to entice players or compete with other casinos, most slot machines have payout rates in the '80s or '90s. State law governs whether the payout rates are published or posted near the machines themselves.


Roulette is a classic casino game was invented by the French (the name means 'little wheel'). A spinning wheel is divided into 38 spaces, each space containing a number from one to 36. The other two spaces have the numbers 0 and 00. The spaces are also divided between the colors red and black (the 0 and 00 spaces are green). A metal ball is dropped onto the wheel as it spins, rolls and bounces around a bit, and eventually settles into one of the spaces. The players bet on which space the ball will end up in. Bets can be placed in single numbers, various combinations of two or more numbers, even or odd numbers, red or black spaces or sets of a dozen numbers at once. While the house edge varies (different bets have different payouts), it is roughly between five and seven percent.

Roulette wheel Roulette wheel
Roulette wheel
Photo courtesy of Toni Lozano


Craps is a dice game, and is often considered the most complicated casino game. The players bet on the outcome of the roll of two six-sided dice, or on a series of consecutive rolls. The casino edge in craps is about 1.5 percent. Explaining all the details of betting on craps is beyond the scope of this article.

Craps game Craps game
Craps game
©2007 Martin Ouellet

We'll look at more casino games in the next section.