A stripper deck is a deck of playing cards, used by usually novice magicians to perform various effects. It has the disadvantage that borrowed cards can't be used - but the advantage that fewer sleights are neccesary to perform the same effect.
The basic deck is a full pack of 52 cards, but rather than being rectangular, they are trapezoidal - with the short sides parallel, and the long sides tapered by the same small amount each side. The tapering is minute - less than a millimetre from end to end, so it is not visible to the human eye.
The benefit of the taper becomes apparent as somebody is asked to pick a card. The deck is rotated about the plane of the cards, so that when the card is replaced the taper now runs the other way to the rest of the deck and the corners on the long side stick out just slightly from the remaining pack.
The 'stripper' name comes about because the chosen card can now be stripped from the pack, by holding the long edge of the cards between finger and thumb as close as possible to the short end. The card may be subtley withdrawn, or the pack cut, in which case the chosen card will now be on the bottom.
Although the risk of being found out with a stripper deck is low, it is usually worth getting a standard pack in the same series - strippers are available in Bicycle brand, at least. The pack should be switched before handing out for examination as a safeguard.
Probably all of the effects of a stripper deck can be performed using normal card control - by holding a marker on the chosen card as they are shuffled. The beginner will go for strippers, the professional will use sleights - the advantage being that they can now perform the same tricks with a borrowed pack, always far more impressive.
The repertoire of a stripper deck is less mind-blowing than a svengali deck, but the cards stand up to scrutiny, and should not be dismissed offhand - they certainly have a place in the magic box of anyone who hasn't yet mastered the complicated sleights necessary for the effects it can perform.