Casino games are the common term used to define wagering on casino gambling devices such as slots, roulette, poker, and blackjack. A casino provides a variety of games where players wager by winning or losing bets, the winnings usually being paid out to the winners. To qualify as a casino game, the device must be able to take bets, which are then held by the casino. In the same way that a land-based casino can offer a variety of games, a computer casino can offer gamblers with casino games that are based on luck and chance.

The earliest forms of casino games were blackjack and pokers. Blackjack was the first of the casino gambling devices to be fully integrated with machines. The earliest pokers were also played on machines, but this later changed as many pokers in circulation were operated via a deck of cards that each had a small bet. These early pokers usually involved two people, both of whom concealed a card from one another until the other had a chance to reveal it.

In the same way as online casinos can be differentiated by whether they offer games based on random chance or those that have specific odds as part of their design, so too can casinos be differentiated by the ways that they vary the odds offered by the machines. Roulette offers a fixed set of odds, but the odds are modified slightly for specific spin combinations. When these combinations are printed on the machine, they are chosen by the machine and not by the player. The odds are thus modified slightly to favor the player. This is also true of blackjack and other roulette games where the odds are fixed and not dependent upon what the individual spin combinations are.

Online casinos offer a variety of games that can all have odds varying by the type of game and the type of machine being operated. Some of these slots, which may not have additional blackjack or craps games onsite. Online slot machines are not dependent on luck, but on a random number generator. In online casinos offering roulette and other casino games, players may play either for money or for time, or may play for both. Many slot players prefer to play both for the added excitement of trying to beat the odds.

In online casinos that offer progressive slots, the outcome of the spins on these machines is determined by how much money has been played so far. If more money is wagered on the machine than it has paid out already, the outcome will depend on the total amount still available on the machine, and thus no longer on which spin the ball will fall. Thus, the odds on these machines are changed slightly to favor the slot player.

The use of software to control the machines is commonplace in the world of casino games, from poker to slot machines and blackjack to roulette and progressive slots. Software engineers and casino operators have worked together to create software that, when programmed properly, allows for the re-routing of bets through software programs and random number generators. With this, casino goers no longer have to worry about whether or not they have chosen the right card at the right time, or if they have picked the numbers that should be rolled off the reels. They can instead put their trust in the capabilities of the software and let the machine do the work. After all, even the best lottery software can only crumple the odds in a single way: with the luck of a thousand bad luck rolls, then it becomes statistically impossible to win the jackpot at any frequency.