Cheating at Blackjack
Cheating at blackjack doesn't include card counting. The kind of cheating described here is actual cheating that is highly risky and can get you in trouble with the law. This page isn't a "how to" guide to blackjack cheating either, but rather an interesting page of sneaky methods used in the past by shady players.
Card counting isn't considered cheating because you are using information that is available to everyone else at the table. It is actually an acquired skill that takes time to develop and requires a high level of intelligence. In fact, some players may not even be able to help themselves due to good memory after they learn card counting! Although if you are caught card counting, you can be thrown out and banned from a casino, but it's very hard to get caught.
Cheating Blackjack Dealers
This is potentially one of the most damaging types of cheating to a casino. In some cases a player may either be friends with the dealer or makes some type of deal to split the winnings in collusion. The dealer will purposely lose or somehow signal to the players what cards they have. This is why security cameras (eye in the sky) and pit bosses are in place. This way the dealer can be watched.
Switching Cards - Sleight of Hand
This kind of method is switching cards that are up your sleeve with your actual cards. It requires great skill not to be caught using a sleight of the hand method. At the same time, you have to be able to walk into a casino and up to a table and not have a bunch of fake cards fall out or even come into view.
Not only do you have to be able to put a fake card on the table, you also need to be able to take one of the real cards off the table at the same time without anyone noticing. It just requires so many actions to do this successfully that it's best just to not do it. Getting caught will cost you more money than you could ever make playing blackjack this way.
Marking the Blackjack Cards
Marking the cards is an old and sneaky way to cheat. This can be done by bending the cards or marking them in some way such as scratching an indentation with your finger nail. This is an act of cheating that the dealer may not be aware of but it is very risky. Another way to mark the cards is getting a special type of ink or material that can be seen from a low angle of incline where a player could see it but not a dealer looking down from a high angle of incline. Similar to optical security features on paper money.
It works by letting the players know what the face down card is from the dealer. Usually a cheating player will mark the ten cards because they are more numerous in the deck and they are the strategic cards.
The casinos take a few actions to prevent this kind of cheating. First, some casinos have the pit bosses always checking the cards or even replacing the whole shoe with new decks of cards every so often. They even go as far as putting in a whole new deck of cards every time the deck needs to be shuffled.
Blackjack Spooking
This is a very interesting type of cheating and requires more than one person. First you have one person playing the card and another person known as the "spook" usually playing at a table positioned behind the dealer. Spooking involves this person trying to see what cards the dealer has and then signals this to the person playing the game. In some cases the dealer may actually be involved in the cheating by purposely exposing the cards. This is also something that sloppy or inexperienced dealers accidently tend to do.
These are some of the most common methods and also ones that casinos are very familiar with. I wouldn't recommend doing any of these because getting caught would result in legal problems, unlike getting caught card counting. Also, you have no idea what security could do to you and you have no idea what type of people you would be upsetting. This just brings up memories of movies about casinos being run by mobsters. You don't want to end up in the wrong place at the wrong time with the wrong people, especially if you just got caught stealing from them.