A deck of marked cards is a special type of playing card that has secret markings on its back. These markings are invisible to the naked eye, but they are easily read by trained readers.
They can be used in magic, gambling and other private games. However, they are often considered a form of cheating by purists.
It should be easy to read
A good marked deck should be easy to read and ideally look like a normal deck. The markings should be large enough to read from a distance, but not so big that the deck looks too suspicious.
It should also be designed with the long edges of the cards showing the markings so that you can easily identify a card when displaying it in a spread or fan. This is critical because it makes it much easier for your spectator to spot a card that they would otherwise not be able to see.
There are many different types of markings systems on the market, but most of them depend on either a reader system or a coded system. A deck with a reader system will have a simple message on the back of each card that will tell you what suit and value it is.
Similarly, decks with a coded system will have codes or clues that can be read to reveal the identity of a card. This can be done by reading the backs of the cards, or it can be achieved with other methods such as a hidden camera or sensor.
A deck of marked cards is an extremely diabolical secret weapon that enables you to fool your audience into thinking you’re using a normal deck, even when you’re not. However, it’s important to use them in ways that are natural and judicious, and to be selective about the tricks you perform.
It should be easy to conceal
A good deck of marked cards should have features that will conceal its markings from a casual glance. This may include clever use of design elements, or it might be as simple as using the right color ink to make the mark.
This is a great way to keep your deck clean from curious spectators who might be tempted to try their luck by playing with your deck if you aren’t careful. It is also a great way to show off some of the more intricate aspects of a deck’s back design without drawing too much attention to them.
Ideally, a deck of marked cards should have something that’s not just obvious to the layman, but will be a pleasure for you to perform. This can be a card that is printed on high quality paper, or even a piece of art that distracts from the markings while still being functional and pleasing to the eye.
There are many different types of marked decks, but the best ones will be easy to read and conceal. For example, a deck that uses an optical marking system (aka reader system) or has been marked with the tiniest of marks is likely to be the best card to use for your next close-up routine.
It should be easy to perform
There are a number of routines that can be performed with a deck of marked cards. These include The Keeper of Secrets and Thought Transfer.
The trick is that you must choose a marked deck with a design that cleverly hides the markings without being too obvious to your spectators. A marked deck should look as if it were a normal deck of cards, but with the markings cleverly placed within the artwork on the card back.
Another important factor is that a marked deck must be easy to read. This means that unless your spectator takes the deck and looks carefully at the backs they will never notice it’s a marked deck.
A very common way to do this is with a punch deal where you use tiny bumps in the cards that you can read by touch. This can be done in conjunction with an expert second deal to find the desired card.
This makes a deck of marked cards a very practical tool to have in your arsenal. It is one of the best safety nets in all card magic and can save you from having to perform a mistakenly selected card or a miscalculated number.