Almost every poker player has run into a cheater at one time or another. Cheaters usually have little or no skill at the game, but are very good at manipulating the cards to their advantage, and at giving themselves unfair advantages over honest players. Where honest players spend their time learning all they can about the game, cheaters spend their time honing their cheating skills, and looking for new cheats to learn. They make minimal effort to advance their game in honest ways.

The method that is easiest for the cheater is collusion. It is very hard to catch a player in the cheat of collusion, and it is next to impossible to prove. Collusion occurs when two or more poker players will secretly work together at the same poker table. They usually plan to merge and split their winnings once the game is over, thereby often enabling them to double their winnings. There is little skill necessary on the part of the cheater to be able to pull this off. Collusion does pose a large threat to the other players at the table.

Players that are in collusion may do several different things to help each other during the game. They may get together beforehand and decide that one of them will distract the other players at the table, so that the other, who will probably be the next dealer, may stack the deck in their favor.

When players are acting together in collusion, one player may flash their hand so that the other player can see it. This lets the other player know what cards that player has, so that they can help them in anyway possible to win the hand.

Occasionally, the players in collusion may speak a different language than the other players at the table. They will use this to their advantage, as they can discuss the game without the other players becoming too suspicious of their actions. This may also be used as a method of distraction, getting the other players to lose focus on their games, in turn giving the players in collusion further advantage.

Sometimes, players that are in collusion will have signals they secretly give each other during the game. Other players most likely will not recognize the signals for what they are. They may use signals to let the other player know how strong their hand is, or they may also use signals when placing bets.

Sandwiching occurs when the only players left at the table are the two that are in collusion, and one presumably honest player. It is to the benefit of the cheaters to bet back and forth with each other, which will force the other player to see their bets or fold. Cheaters will use this to make their pot bigger, so that they will have more earnings to split at the end of the game. If the colluders place maximum bets, the other player will usually be bullied out of the game.