Cheating in poker is any behavior outside the rules intended to give an unfair advantage to one or more players.

Since poker has a wide variety of rules and procedures, hands are played fairly quickly, and numerous people are involved in games, the occurrence of cheating is common. Cheating can be done many ways, including collusion, sleight-of-hand such as bottom dealing or stacking the deck, or the use of physical objects such as marked cards or holdout devices.

Cheating occurs in both friendly games or casinos. Cheats may operate alone, but also may operate in teams or small groups.

Following is a list of terms used to categorize specific card cheats:

• card mechanic -- A card cheat who specializes in sleight-of-hand manipulation of cards, a card sharp.
• base dealer/second dealer -- Also called bottom dealer/second dealer is a cheat that specializes in bottom/second dealing.
• paper player -- A card cheat that exploits the use of marked cards.
• hand mucker -- A card cheat that specializes in switching cards.
• machine player -- A card cheat that uses mechanical holdouts.

Minimal-skill methods

The easiest and most common types of cheating require no ability of manipulation, but rather merely the nerve. Such methods include shorting the pot, avoiding house fees and peeking at other player's cards. However, it is very difficult to prove because when confronted, the first time at least, the cheat often calls the cheating an honest mistake.

One minimal skill method that occurs in non-casino games happens when a player who has folded appoints himself the tender of the pot, stacking chips, counting them, and delivering them to the winning player. Check-chopping is when such a "helpful" player palms a chip. Odorless adhesive can be used for this purpose.

Marked cards

Marked cards are printed or altered so that the cheater can know their value while only looking at the back. The ways of marking are too numerous to mention, but there are certain broad types. A common way of marking cards involves marks on a round design on the card so as to be read like a clock (an ace is marked at one o'clock and so on until the king which is not marked). Shading a card by putting it in the sun or scratching the surface with a razor are ways to mark an already printed deck.

Juice is a substance used to mark cards in a subtle way so as to avoid detection. Once trained, cheaters can read them from across the table.

Decks can be marked while playing using fingernails or by bending or crimping the cards in a position that the cheat can read from across the table.

Skilled methods

A cheat may hand-muck, that is, switch their hand with one they have secretly hidden. This may also be done with a confederate.

A skilled cheat can deal the second card, the bottom card, the second from bottom card, and the middle card. The idea is to cull, or to find the cards one needs, place them at the bottom, top, or any other place the cheat wants, then false deal them to oneself or one's confederate.

One sign of false dealing could be when a dealer grips the deck with the index finger in front of it. This is referred to as the mechanic's grip. It not only allows better control of the cards, but provides cover as, showing the back of the top card, and without moving the hand holding the deck.

Even if a cheat deals himself a powerful hand, he may not win much money if every other player has nothing, so often the cheat will stack two hands, with one player getting a strong hand and the cheater getting an even stronger one.

One method of cheating that involves both great risk and great potential pay-off is the cold deck