A royal x casino game is one in which players gamble cash or chips on various possible random outcomes or combinations of outcomes, often in a casino environment. Such games are also available in online casinos, where permitted by law. Casino games can also be played outside of casinos for entertainment purposes, like in parties or in school competitions, on machines that simulate gambling.

There are three general categories of casino games: gaming machines, table games, and random number games. Gaming machines, such as slot machines and pachinko, are usually played by one player at a time and do not require the involvement of casino employees. Tables games, such as blackjack or craps, involve one or more players who are competing against the house (the casino itself) rather than each other. Table games are usually conducted by casino employees known as croupiers or dealers. Random number games are based on the selection of random numbers, either from a computerized random number generator or from other gaming equipment. Random number games may be played at a table or through the purchase of paper tickets or cards, such as keno or bingo.

Some casino games combine multiple of the above aspects; for example, roulette is a table game conducted by a dealer, that involves random numbers. Casinos may also offer other types of gaming, such as hosting poker games or tournaments where players compete against each other.

In the United States, "table game" is the term used for games of chance such as blackjack, craps, roulette, and baccarat that are played against the casino and operated by one or more live croupiers, as opposed to those played on a mechanical device like a slot machine or against other players instead of the casino, such as standard poker.

Table games are popularly played in casinos and involve some form of legal gambling, but they are also played privately under varying house rules. The term has significance in that some jurisdictions permit casinos to have only slots and no table games. In some states, this law has resulted in casinos employing electronic table games, such as roulette, blackjack, and craps.

Table games found in casinos include:

Electronic table games are versions of the above but played on a machine. This can be split into several categories. Stadium gaming are dealer-dealt games which are performed to a viewing audience akin to a stadium. Although the results come from the dealers, the player bets on terminals at their seat. Heads-up gaming involves players making decisions on their own machine with no interaction from other players. Multiplayer machines are where a player's decision may affect others at the same game, such as when to press the button to roll dice in craps. There are also hybrid games, as in craps, where the player bets on a terminal at the table but the game is managed by a dealer, although with fewer dealers than the non-hybrid version, this saves costs.

Gaming machines found in casinos include:

Random numbers games found in casinos include:

Casino games typically provide a predictable long-term advantage to the casino, or "house", while offering the players the possibility of a short-term gain that in some cases can be large. Some casino games have a skill element, where the players' decisions have an impact on the results. Players possessing sufficient skills to eliminate the inherent long-term disadvantage (the house edge or vigorish) in a casino game are referred to as advantage players.

The players' disadvantage is a result of the casino not paying winning wagers according to the game's "true odds", which are the payouts that would be expected considering the odds of a wager either winning or losing. For example, if a game is played by wagering on the number that would result from the roll of one die, the true odds would be 6 times the amount wagered since there is a 1 in 6 chance of any single number appearing, assuming that the player gets the original amount wagered back. However, the casino may only pay 4 times the amount wagered for a winning wager.

The house edge, or vigorish, is defined as the casino profit expressed as a percentage of the player's original bet. (In games such as blackjack or Spanish 21, the final bet may be several times the original bet, if the player doubles and splits.)