Jack (playing card)

A jack or knave is a playing card which, in traditional French and English decks, pictures a man in the traditional or historic aristocratic dress generally associated with Europe of the 16th or 17th century. The usual rank of a jack, within its suit, plays as if it were an 11 (that is, between the 10 and the queen). As the lowest face (or "court") card, the jack often represents a minimum standard — for example, many poker games require a minimum hand of a pair of jacks ("jacks or better") in order to continue play.

The earliest predecessor of the knave was the thānī nā'ib (second or under-deputy) in the Mamluk card deck. This was the lowest of the three court cards and like all court cards was depicted through abstract art or calligraphy. When brought over to Italy and Spain, the thānī nā'ib was made into an infantry soldier or page ranking below the knight card. In France, where the card was called the valet, the queen was inserted between the king and knight. The knight was subsequently dropped out of non-Tarot decks leaving the valet directly under the queen. The king-queen-valet format then made its way into England.

As early as the mid-16th century the card was known in England as the knave (meaning a male servant of royalty). Although jack was in common usage to designate the knave, the term became more entrenched when, in 1864, American cardmaker Samuel Hart published a deck using "J" instead of "Kn" to designate the lowest-ranking court card. The knave card had been called a jack as part of the terminology of the game All Fours since the 17th century, but this usage was considered common or low class. However, because the card abbreviation for knave was so close to that of the king ("Kn" versus "K"), the two were easily confused. This confusion was even more pronounced after the markings indicating suits and rankings were moved to the corners of the card, a move which enabled players to "fan" a hand of cards without obscuring the individual suits and ranks. The earliest deck known of this type is from 1693, but such positioning did not become widespread until reintroduced by Hart in 1864, together with the knave-to-jack change. Books of card games published in the third quarter of the 19th century still referred to the "knave", however, a term that is still recognized in the United Kingdom. (Note the exclamation by Estella in Charles Dickens's novel Great Expectations: "He calls the knaves, jacks, this boy!")

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