In this effect, a fan of four or five cards is shown and a spectator is asked to think of one of them. Before the spectator tells everyone which card he thought of, the magician removes one card and puts it into his pocket. The card is named and is shown to be gone from the group of cards. The card is then taken from the magician's pocket and displayed. It is the one thought of.
Henry Hardin first advertised this trick, calling it “The Prince's Card Trick”, in Mahatma, Vol. 7 No. 5, Nov. 1903, p 56. Hardin's original method involved showing seven cards as four and, after one card is thought of, putting all four displayed cards as one into the pocket. The three remaining cards, which are similar in appearance, are shown. The thought-of card is gone. It is then removed from the pocket.
A second method appeared in 1907. This used of double-ended cards, which eliminated the need for three extra cards. Both methods are included in T. Nelson Downs's Art of Magic, 1909, p. 80 (ghostwritten by J. N. Hilliard). And with this publication, the prince came a princess, and the sex-change stuck, although “The Prince's Card Trick” appears in the table of contents of Downs's book, and only in the table of contents, for a third method.
Some confusion arose when “The Princess Card Trick” started to be used as the name for a card divination based on a matrix principle; e.g., Al Koran's Professional Presentations, 1968, p. 73; see also Matrix Card Divination.