Slot machines contain RNG a random number generator, which is a computer chip that constantly spits out numbers. The numbers correspond to positions on the reels in the slot machine. When you pull the handle, or push that spin button, you are telling the computer to select numbers. Then the slot machine moves the reels to correspond to the number you picked.
As slot machines become more sophisticated, so have some cheating methods. In those old fashioned coin machines, some cheaters were known to attach a piece of string to the coin, with a paper clip on the end to prevent it from falling in.
The newest way to scam slot machines involves a small computer device that tricks the validator. The device, usually disguised by a $1 bill, has two prongs that are inserted into the bill validator. Once they hit the contact point below the validator, the slot machine will read any bill that’s inserted like it is a $100 bill. The most recent devices don’t even need another bill to work.
they just add credits after hitting the contact point in the slot machine.
However, please know that casinos have already caught, so it is on and the scam is less common than it once was. Slot machines have been fixed so that the devices won’t work. So the only way for a cheater to use the device is to find a machine that hasn’t been updated... Good luck!