This kind of slot fraud is very simple. It includes fake coins or anything else slot machines register as a form of payment. If you are able to manufacture something that the machine "thinks" is a coin, you can use it to make money.
- Fake coins or tokens
Of course, you must be able to manufacture the coins for less than their nominal value. Otherwise, you wouldn’t be very profitable.
There is one famous example of a man who managed to use this technique very successfully. Louis Colavecchio is an American casino counterfeiter also known as "The Coin". He and his gang managed to fabricate considerable amounts of fake coins and casino tokens and use them to make money in the casinos of Atlantic City and Connecticut. He was caught.
If you ever played with a Yo-Yo, you know that it goes down and up when handled correctly. And that’s exactly what a coin on a string does. First, it’s inserted into the slot machine and allowed to go far enough for the machine to register it and start a game. Then it is pulled back out and used again and again.
- Coins on a string (Yo-Yo)
This technique is very similar to fake coins, but it eliminates the need for large-scale fake coin production. With a coin on a string, pretty much everybody could try to defraud a casino. Of course, not everyone did, and not everyone who did was successful.