The old card-switch scam is one of cheaters’ oldest and most obvious methods to manipulate the game. This type of cheating is less common, but it still occurs from time to time. Some people are so desperate for a win that they’ll do anything to get it, even mark cards. Watch CNBC’s American Greed and see some of these extreme examples of what players are willing to do to win.
Some of these methods involve marking the cards before they enter the game, while others involve changing them during play. In either case, a cheater may use their advantage to manipulate game results. The cheater can mark a card in a variety of ways, including by scratching, rubbing ink along the edges, or any other method. They can also change cards by colluding either with another player, or with the dealer.
In some cases the cheating takes place with a group that is working together in order to help one another. These groups are often organized and secretive and meet before the game in order to discuss their plans. They may even work out a coded signal that they can use during the game to communicate with each other. This kind of cheating is usually more difficult to catch.
Other methods of marking cards include abrasions or cutting marks, solvents that smear inks already on the cards and matt agents, which alter the reflectiveness of surfaces. These can be detected visually, or by polarized light. Other methods such as high-resolution imaging of the cards are able to detect fine marks.
Casinos are taking more steps to prevent cheaters from marking their cards. In some cases they use a riffle to test for any animation on the marks. The dealer will riffle a deck of playing cards several times before carefully inspecting them. If the marks are animated, the cards have been marked.
The riffle can also be used to test for invisible inks, which can only be seen with special glasses or contact lenses. These inks may not be illegal, but they’re not considered fair.
A casino can also use new technology to track players and find teams of cheaters. NORA is one example of a system that can identify a group of cheaters through public records checks and finding out their relationship. This technology can be a huge help in preventing cheating, and it is being used in many different types of casinos now.