Money Cheats
In the early days of slot machines cheating was as simple as taping a piece of string to a coin, today coin shaving and counterfeit tokens are whats being used by slot cheats.String and Coin - This is possibly the simplest form of cheating that can be done on a slot machine. The idea is simple you tape a length of string to a coin and insert that coin into the slot machine. Once the machine registers the coin drop a tug on the string and the coin returns to the player. Repeating this process adds credits to the machine without spending anything. Players using this method were refered to as Yo-Yo players because of the action of pulling the string multiple times looks like they are playing with a Yo-Yo. The biggest draw back to this system is the fact that there is a string sticking out of the coin slot of the slot machine. It would be pretty hard to explain why you have a string in a slot machine. With the discovery of this cheating method, vendors were able to come up with a device to prevent the coins from returning up the coin shute. The only place this cheating method is going to work is in a slot machine museum and the machines there don't pay-out.
Shaved Coins - Some cleaver people discovered that if you shave about 0.040" off a quarter the slot machine will still register the coin being dropped into the machine but are immediately discharged from the machine. This produced the same results as the string trick but without the string sticking out of the machine. As you can see in the image to the right, the coin on the right is slightly smaller and unless close attention is paid to the coin it would be easily over looked. While this method is easier to use then the string method, the inserting a coin and having it pop right back out while registering a credit is sure to draw some attention eventually. Vendors have also developed more sophisticated optical coin readers to evaluate each coin inserted and reject those coins that don't 'measure' up.
Counterfeit Money - This one isn't specifically a slot cheat but it certainly affects slot machines more often then other games in the casino. There are some counterfeit bills that are good enough to pass the electronic eye of the slot machine. This offers the cheat a way of 'laundering' the money they made. How this works is that the cheat would play a machine that returns a high percentage of the money played. So if the cheat got 95% of every dollar played they would have .95 of real money sticking the casino with the fake money. The fake money won't be detected until the slot machine is emptied and the money counted and by then the cheat can be long gone. The downside of this method is obvious. Counter fitting money is a federal crime that the FBI and the Treasury Department take very seriously.
Counterfeit Tokens - Many casinos have switched their slot machines from accepting coins to accepting casino tokens. The original idea behind that was that the players would need to exchange legal tender for casino tokens which can only be used in their slot and video poker machines. Since altered money could not be used at the slot machines then that would stop the cheating. Well this worked for a while until some decided that they could make their own tokens and spend those at the casino. The process for making your own tokens is pretty simple in theory. First you need a token you want to copy, this just requires a visit to the casino of choice and 'purchase' a few tokens being sure to keep one on your way out. Next you make a mold(s) of the token and with a small investment in easily and legal materials, you melt some metal and pour it into the mold(s). Once the tokens have cooled you remove them from the mold, remove any excess material and polish them up.
The draw back to this method is that it is very hard and expensive to make quality counterfeit tokens. The size, weight, look and feel all need to be exact, if just one of these things is off it will be easy to identify them and you. Vendors and Casinos are very vigilant about this type of cheating. There are some very good counterfeit tokens out there and some may even have ended up in circulation. If this was allowed to go unchecked, not only would the casino's be affected but legitimate players might be scrutinized as cheaters.
Shaved Tokens - Much like the Shaved Coins method, cheaters get a number of tokens and shave them down so that the machine registers it as a credit but does not recognize it as a legitimate token and spits it back out. The benefits and draw backs of the shaved token are the same as the shaved coin.
Slugs - Slugs are metal circles that match the diameter, width, weight and magnetic properties of a coin or token but have no designs on them. When dropped into a machine they would be close enough to the real coins or tokens that the machine would accept them without a problem. Unless a player is spotted using slugs is almost impossible until the money is counted from the slot machine to catch a player using slugs to cheat the casino. With better technology and video cameras covering the slot areas you might make it out of the casino but they will certainly report you to the police as a suspect, and they'll have your picture to share with the police.
Foreign Coins - Slot cheats quickly learned that there are some foreign coins that are sloe enough to American currency that they are able to fool the coin counters on slot machine into believing that they are in fact American Currency. This may not seem like a huge problem but the when the actualy value of that coin might be 1/10th of the cost of it's American counterpart it's being mistaken for you can see how this could quickly become a problem.
Coin Emulation - This cheat consists of a device that is inserted into the coin slot of a slot machine and once in place and activated it uses electronics to simulates the signals to the coin comparator that coins are being added to the machine. On some machines it is even possible to add several hundred coins in a fraction of a second. With this cheat like any other money cheat, the cheater need not play through all the fake money to make some money. Once the fake money is added to the machine the cheater need only to 'Cash Out' to turn that fake money into real money.
Bill Validator Fraud - This one isn't specifically a slot cheat but it certainly affects slot machines more often then other games in the casino. There are some counterfeit bills that are good enough to pass the electronic eye of the slot machine. This offers the cheat a way of 'laundering' the money they made. How this works is that the cheat would play a machine that returns a high percentage of the money played. So if the cheat got 95% of every dollar played they would have .95 of real money sticking the casino with the fake money. The fake money won't be detected until the slot machine is emptied and the money counted and by then the cheat can be long gone. The downside of this method is obvious. Counter fitting money is a federal crime that the FBI and the Treasury Department take very seriously.
The counterfeit money used by casino cheats is specifically designed to beat the checks and balances of the bill validators that the slot machines use. By designing money to beat the bill validator the cheat doesn't have to worry about the money being discovered until the casino empties that machine and counts the money. This is a very effective way of laundering fake money even if the return is only 95%. Over the years the Bill Validators have become more sophisticated as the counterfeiters have become more sophisticated. Today all but the most advanced counterfeit bills are caught and will the cooperation of the treasury department the days of counterfeit bills being played at slot machines are numbered.
Like the string on a coin trick there is a similar trick that was used for bills and early bill validators. Cheats would attach to a bill a length of clear packing tape, laminate or other thin plastic to create a 'tail' of one end of the bill. This bill would be inserted into the bill validator, once the machine registered the credits the 'tail' would be pulled and the bill would return to the cheat. Some variation on this cheat include the use of a separate flat piece of plastic or this metal to be used in the Bill Validator to retrieve the bill a third variation has fishing line attached to the bill instead of the plastic tail to retrieve the bill. Like the string on a coin trick the Bill Validators have been upgraded to detect the modifications to the bills, the plastic tails, and mechanical improvements have been added to prevent the bills from being removed from the machine back through the bill validator.