As a magician, I am always accused of using marked cards. A simple strategy I have developed to solve this problem is to open new decks and give the cards away at the end of a performance as a proof of fairness.
This usually satisfies suspicious viewers, but the truth is, I could confidently give them one of a dozen types of marked games that they would never suspect, let alone detect the secret information on those cards.
This does not mean that all marked decks are created equal.
Several types are extremely easy to identify if you know what to look for, and many are sold as novelty items for “entertainment purposes only” with a piece of paper or a printed card to learn how to read the code.
More sophisticated systems depend on learning variations in patterns, colors or shades on card surfaces. But not all marked cards are eye-dependent and some are designed to be read only by touch.
Others are designed to work with hidden cameras, sensors or other concealed technology and cannot be detected without the aid of an appropriate device.
Some systems can be blatant to those in the know, but completely invisible to casual gamers.
There are several ways to prepare marked cards, but an important question is: how do cheaters get them into a game? They can’t just take a deck out of their pocket and say “hey, let’s play with this! Or they can be blamed if the dirty work is discovered later.
In this article, we will discuss pre-prepared marking systems.
The most obvious method is to apply marks to a legitimate game. There are many ways to do this that require varying degrees of skill.
Obviously, cheaters spend a lot of time practicing these systems and some get so good at scoring cards that their work should be on display in a gallery!
Subtly change the design of the back of the cards
“Block out work” uses inks or paints that can subtly adjust the back design of a card to signal color and / or value. A needle can also be used to apply “scratch work” to a card and I have seen intricate work applied to the backs of cards that would be worthy of a master engraver.
Partially invisible inks have long been a favorite method of cheaters who train their eyes to see what others cannot. The green and yellow pigments on red back playing cards can be applied in such a way that only those looking for the marks will notice. I’ve seen heavily branded versions of these decks that seemed obvious to me but were undetectable to the untrained eye.
Some “jobs” are completely invisible to the human eye and require special glasses or contact lenses to see – but we’ll discuss these methods at another time.
Cheaters make a special “juice” to change the shades of pigments
“Juice” is a simple recipe for creating variations in shade of pigments on the back of certain card designs.
The making and application of the juice are secrets passed down from one mechanic to another. The strength of this juice depends on the skill of the cheater when reading the speckle patterns on the backs of the cards.
To a savvy eye, even a super subtle juice can be read across a crowded room, but if the marks are too heavy, honest players might notice something on the cards that isn’t quite right.
Professional juice is impossible to detect without the required training.
A story to prove it …
One morning, I had lunch with two friends, one of whom had made expert juice for us to add to our collections.
The decks marked were red backed Bee cards with a simple diamond pattern on the back and my friend’s work was outstanding. My other friend was having trouble reading the notes, so I handed him my board to try. What he didn’t realize was that I had an unmarked Bee deck with me and replaced the marked cards we were looking for with unmarked cards!
He struggled to see the juice that wasn’t there, then held out a card so we could read it from across the table. My friend who had created the branded decks immediately called him and was one hundred percent right! I was completely fooled until he repeated the feat a few times and realized he could see the cards sticking together because the restaurant wall was mirrored!
We let our friend play the joke and luckily for me he didn’t drive me through the desert with a shovel in the trunk.
Using “Punch Work” to create cards Feel Different
The shapes of the cards can be altered by removing the hair-like waves from the edges of the cards for use with various dishonest techniques. Shaved cards can be located by shuffling or controlled in or out of a player’s hand.
“Punch work” is where a cheater creates tiny bumps on the back or face of a card in an attempt to identify those cards during a transaction, using only the sense of touch. There are devices designed to create perfect, imperceptible little dots on a playing card, but many cheaters make their own or find perfect substitutes they can buy anywhere.
A professional shared his method with me late one night in Las Vegas: We walked into a well-known store and requested a common medical item that not only allowed him to puncture an entire bridge quickly, but also make sure that every little bump was the same. This last part was essential since his method was to sneak the game into the bathroom while everyone paused and punched the cards they wanted in seconds without accidentally pushing a needle through one of the cards.
More importantly, if he was suspected of anything, the device he was using would appear to be for his health, whereas a typical cheater’s punch would be clear evidence of foul play.
Punching job is commonly used with an expert second case with bumps so small you’d be lucky to feel them, even if you tried to find something.
Strike deals require a sense of touch combined with perfect timing to execute a second trade when a marked / desired card comes up.
The most direct application is to deal the cards honestly until you smell a punch card, then deal the second card until you reach the player you want to deal the marked card to; then repeat for each game turn.
In fact, there are much more sophisticated ways to use a perforated deck.
Imagine a deck that signaled every time you dealt a high card in a game of Kansas City Lowball. You now know which hand is broken by one or more high cards and which player could play a low seven.
Information alone should be enough to give a decent player an edge so that cheaters using a punch card like this learn to deal quickly and fairly while still feeling those little marks as they deal.
Close a deck of cards to make it look new
Another consideration when creating marked cards is how to close a deck without proof that the content has been tampered with.
I’m here to tell you that it’s both possible and in some cases quite easy to do. With enough time, anyone can make their way through a sealed bridge that allows the box to be glued together as if nothing had happened.
Cellophane wrapping, however, can be tricky, but there are also several solutions for this.
Many years ago, in a bar in Madrid, the topic of reclosing card games was brought up while sharing ideas with a legendary Spanish card cheater. He told me he had a perfect solution that didn’t require any glue or special equipment and could easily be done in almost any situation.
I’m not going to share this method with you (or anyone else – I swore to keep it a secret) but I can tell you this: XXXXXX took a sealed game, opened it, took it all out. the cards then resealed the box using a traditional method – but this left the frayed cellophane wrapping to process.
Smiling, XXXXXX took two common items from his pocket and in ten seconds the box was perfectly closed; previously torn cellophane repaired by magic.
I now had a perfectly sealed (empty) card box and a beautiful secret that I have used since.
The lesson here is simple: Other than a few ranking methods, a properly marked deck is difficult to spot unless you know exactly what you’re looking for and how to see or feel it work.
If marked cards are used against you, it may be easier to identify by the way the cheaters act than to uncover the secret work on a professionally marked game. In my experience, amateur cheaters have no idea how to use a marked deck without it being obvious that they are reading both sides of the cards!