Cheating Device Spotlight - Magnetic Dice

A description of the various ways magnets have been used to gaff dice.

9/18/20224 min read

The Magnetic Stuff

Before we start talking about “mag” dice we must first understand magnetism and electromagnets. Permanent magnets also known as ferromagnetic are magnetized by an external magnetic field and remain magnetic even after the field is removed. Common metals in order of most susceptibility to magnetism are: Iron, cobalt and nickel. These are the most prevalent permanent magnets metals. Horseshoe magnets are a good example of a permanent magnet. They are made from Alnico, often a combination of aluminum, nickel and cobalt but they can be constructed of copper, iron and titanium as well.

Electromagnets differ from permanent magnets in one very important way. They can be turned on or off as needed. Creating an electromagnet is fairly simple, just wrap copper wire tightly around a weak ferromagnetic metal such as steel. When electricity is applied to the copper wire the wrapped metal becomes a magnet. The more wire, the stronger the magnetic attraction. The on/off feature of an electromagnet is extremely useful for the dice cheat. He controls when the gaff is on or off. On for himself and off for everybody else.

Surprisingly, magnetitic dice (also known as electronic dice or juiced dice) have been around since the 1800’s. A newspaper article from Fort Scott, Kansas “The Fair Play” dated May 26th, 1890, reports on a dice table with a horseshoe shaped magnet with wire wrapped around it under a ten-inch square steal plate located in the center of said table. The electromagnet was engaged by turning a knob located on the one of the table legs. attached to the device. The report goes on to explain the gaffed table has been in use for 15 years and was being refurbished to be sent to a new steer joint somewhere else in the country. This account puts the earliest known date for a juiced dice table around 1875.

There are two ways to create juiced dice. The first process is identical to adding weight to a cube, instead of using a heavy metal use a magnetic metal. The problem with this method is that the loads are visible on transparent dice and the dice wobble when spun on a balancing caliper.

A better, more sophisticated method is to mix a small amount of ferromagnetic carbide particles in with the paint used on the spots. These dice will spin like “fairs” on a caliper and weigh very close to true due to the small amount of dense material being used. These electronic dice just need to be charged to magnetize the desired numbers. The orientation of the die in the charger determines it’s north/south polarity.

A 3-4 electronic die can come up with either number depending on the orientation of the magnet used to control the die. If the magnet is aligned north/south the 3 will appear. A south/north polarity forces the 4 to come up. Theoretically, a die could be juiced to throw any number combination if all number were loaded with a charged metal. As discussed, the orientation of the controlling magnets would determine the rolled number. What if several electromagnets each aligned for a different number were concealed under a playing surface? The cheat would just turn on the magnet that forces the desired number, while leaving the other magnets in the off position.

Juiced dice are not percentage dice. They are a sure thing. There is a drawback associated with these sure dice, mag dice can look unnatural when rolled. This is why they are most frequently used in games that use a cup or other concealment to shake the dice. The biggest negative for “mag” dice is that anyone with a magnet can identify them.

Radio Controlled Dice

There are reports of dice being controlled remotely via a radio signal. The FFC was actually interesting in this gaff about 50 years ago. They inspected a craps table after the Maryland state police informed them, they had one, confiscated in a recent illegal gambling bust. It turned out the table was just juiced and worked with “mag” dice. The radio-controlled aspect was just to turn the electromagnets on and off again.

Induction or Inductive Dice

There are “induction dice” for sale on the internet, sold by crooked dealers. These dice contain a battery and a transmitter imbedded in the actual dice, paired with the remote vibrator; these cubes do not roll desired numbers; they simply inform the person holding the vibrating receiver what number has rolled. It’s supposed to work by sending six unique signals from the die, each signal corresponding to the numbers on the die face. A long vibration might indicate a one has been rolled while no vibration shows a six has turned up. Induction dice must be opaque to conceal the electronic in the die and will work as long the imbedded battery still has juice. The seller claims 100% accuracy. They also claim the gaff is undetectable, which is not true. The embedded battery will react to a magnet whenever it’s near the inductive die.

The dice are meant for use with dice cups. On some dice games dice are rolled using a cup and the results are not known immediately to the players. There are situations where knowing what rolled before the dice are revealed to all is advantageous. I can picture magicians using induction dice to entertain and delight. Conductive dice would make the magician appear telepathic for sure.


In Las Vegas in 1967 there was concern from the gaming industry around the radioactive substance, Cobolt-60. One report suggested the casino industry may have lost $300K to this high-tech dangerous gaff. Other media reports from that time explained that the Gaming Board spoke the inventor of a system using Cobalt-60 rubbed on the dice surface and a pulsating electronic device. According to inventor the Cobalt-60 system is superior to traditional magnetic dice because the dice will not react to a magnetic field but can be controlled as well or better than “mag” dice.

The pulsating electronic device, when switched on, was said to be able to control the outcome of dice rolls. This sounds pretty far-fetched on the surface, but the Gaming Board did the proper due diligence, attempting to discover if it was a feasible cheating method. The Board contacted government scientists, specializing in nuclear energy. The scientists laughed off the idea, saying it is ridiculous. With this information in hand the Nevada Gaming Control Board declared the whole thing a hoax.