The jack of clubs is the key card in the wonderful gambler's tale below. When I first heard it (from my father) the card was the Ace of Spades and the fork was a knife, but I think this version makes the tale even better:

The story is told of a noted sharper of distinction, a foreigner, whose hand was thrust through with a fork by his adversary, Captain Roche, and thus nailed to the table, with this cool expression of concern - �I ask your pardon, sir, if you have not the knave of clubs under your hand�. (Ref. 1)

It was the same card that denied Bridge expert Alan Sontag the chance to play for the USA in the Bermuda Bowl in 1974. He was in a five Spade contract which he made plus one due to the favourable position of the jack of clubs (a 40% chance according to Sontag). Unfortunately for him when his opposing team played the same cards they bid and made the small Spade slam, winning 11 international match points which was a mortal blow. As Sontag put it in his book 'The Bridge Bum', this jack of clubs had 'ruined his whole year' (Ref. 2). Later, a friend presented him with a plaque engraved with the card.

It is also the card glued to the dust wrapper of my copy of Playing Cards, History of the Pack and Explanations of Its Many Secrets by W. Gurney Benham, 1931. There were 53 dust wrappers produced each with a different card on the front.

References

1. STEINMETZ, Andrew. The Gaming Table. London: Tinsley Brothers, 1870. Vol II, Chapter II, p.34
2. SONTAG, Alan. The Bridge Bum. New York: William Morrow Inc, 1977. Chapter 10. p.166