Rigged decks (also sometimes called “marked” card decks) have been utilized by magicians and card cheats for about as long as card decks themselves have been around. 

Would you spot a marked deck if you encountered one at a game or club? Anyone who plays cards for pleasure, awards or cash should know what to look for.

Here are some of the signs that you might be playing bridge with a less-than-fair deck of cards.

Check Your Decks

Card decks are a lot like guitars; both of them have serial numbers, and both of them can be compared to pictures and international database records to ensure that you aren’t looking at a fake.

The first sign of a marked, duplicate or fake card deck will be that something, somewhere looks different than usual.

Standard manufacturers like Bicycle should have comparison images; USPCC serial numbers can also be compared to the series of playing cards you’re playing with. Standard and popular manufacturers are pretty easy to check up on, while lesser-known card manufacturers won’t have this database to compare to.

How Marked Decks Are Used

What do you do with a marked deck? 

Well, usually, cheat. 

Marked decks point out the high-value cards in the deck with small differences that will only be visible, noticeable or obvious to some players at the table. It’s done for an unfair advantage (and thankfully, it’s impossible to achieve in the world of online bridge where card decks are virtual and the order remains random).

Rigged decks can exist almost everywhere card decks do.

If you think someone is cheating with a rigged deck, challenge them with a substitute of your own choice. It’s the quickest way to figure out if there might be more to consider.

How Decks Are Marked

Examine suspicious decks, and examine them up close. 

Here are some of the ways decks can be marked (and what you should be looking for).

Cutting Corners

Sometimes the only difference in a marked deck can be the size of the cards – or small physical markings, like folds or cuts in the cards. Spotting this requires a first suspicion and a pretty close examination of the cards from there. 

Color or Shade Changes

When the color or shade of certain cards appear just a little different to the standard, it might be a marked deck. These changes are meant to be subtle, and will only be seen by someone who is trained to spot the differences (or when comparing the entire, real deck by comparison).

Pattern Changes

Where changes in the shade of the cards are too obvious or the method is impractical, sometimes the card backs will be changed just a little – and this change is usually extremely minute and hard to see unless you already know what you’re looking for. 

Again, in some way, cards will be different to the standard.

Sheen Changes

Some cards shine, some cards don’t. If this appears in the same deck of cards and only to certain cards, beware: changes in sheen can be created by altering card backs and might be extremely subtle. To see this alteration, you might require direct lighting applied to the cards.

Ink Changes

Sometimes, rigged decks are achieved by altering the ink. From there, the cheater can see this ink by specific means depending on which type of ink is being used – sometimes, with glasses, contact lenses or ultraviolet light.

Advanced Ink Changes

More advanced ink changes can be spotted with means of a specialized computer display – and this, apparently, is one of the more high-tech versions of rigging a card deck which would require someone on the outside of the game together with communication. It’s elaborate and sounds slightly mad, but people will – and have.