Stripper deck

A trick deck usually refers to a deck of playing cards that has been altered in some way to allow magicians to perform certain card tricks where sleight of hand would be too difficult or impractical.

A stripper deck (also known as a tapered deck, wizard deck, or biseauté deck) allows the magician to control the main location of a card or group of cards easily within the pack. Even after being shuffled into the deck by a spectator, the magician can cut to a selected card. Similarly, even after being lost in different parts of the deck, the magician can move multiple cards to the bottom or top of the deck with a few innocent shuffles.

Unlike the invisible or svengali deck, the stripper deck can be handled by an audience member unfamiliar with the concept and can withstand a modest amount of scrutiny without exposing the secret; however, this deck is found in a number of beginners' magic kits, so the secret is well-known, even among non-magicians.

The cards of a stripper deck are slightly tapered, so that the sides no longer form a perfect rectangle. The change is slight enough to be undetected by visual inspection or even casual handling, but if a single card is rotated 180° so that it's tapered in the opposite direction from the rest of the deck, the card's broad end can easily be detected, by feel or even by sight, among the narrow ends of the rest of the deck. At this point the magician can select the target card through sleight of hand.

Many of the effects achieved with a stripper deck can also be accomplished with sleight of hand.

The deck alternates between normal cards and shortened cards, with the shortened cards all of the same number and suit. When the deck is riffled front to back, only the normal cards are visible; when it is riffled back to front, only the shortened cards are visible.

The deck can be dribbled or riffled to create the illusion that the deck is completely ordinary. It can even be shuffled. One basic trick involves a spectator choosing a card from the deck and returning it; the card can then appear practically anywhere in the deck, making tricks like the Ambitious card incredibly simple. The final and most stunning trick is when all the cards are suddenly presented as being all the same as the initially chosen card.

Joe Stuthard's Trilby and Bi-Co Trilby Decks are variations on this deck. In the 1960s and 1970s, Marshall Brodien sold 17 million Svengali decks under the name TV Magic Cards. While the Svengali Deck allows for the easy performance of seemingly complex tricks, the conjurer cannot allow an audience member to examine the deck. The use of a Svengali Deck can also be detected by its characteristic faster riffle and sound. Finally, because the deck is widely sold in joke and novelty shops, many laypeople are familiar with it.

...
Wikipedia