|As with all games over a certain age, chess has been associated with a number of anecdotes; some of these relate to games that have gotten out of hand and resulted in the murder of one of the players involved. The reliability of many of these anecdotes is suspect, but at least some appear to be based in fact.|
Possibly the anecdote with the most supporting evidence is given in the book Chess or the King´s game (1616) by Augustus, Duke of Lüneburg, who claimed to have obtained it from an old Bavarian Chronicle, then in the library of Marcus Welsor but now lost. The anecdote states that Okarius (also spelt Okar or Otkar), the prince of Bavaria, had a son of great promise residing at the Court of King Pippin. One day Pippin´s son was playing chess with the young Prince of Bavaria, and became so enraged at repeatedly losing that he hit the latter on the temple with one of his rooks and killed him on the spot. This anecdote is repeated in another Bavarian Chronicle, and in a work by Metellus of Tegernsee about Saint Quirin and other documents refer to his death while at Pippin´s court.
King Canute (c. 994–1035) of Denmark, England and Norway, is said by some to have ordered an earl killed after a disagreement about a chess game. By one account, the king made an illegal move that angered Earl Ulf, who knocked over the board and stormed off, after which the king sent someone to kill him.
In Ambrose Bierce´s short story "Moxon´s Master," a chess-playing robot murders its creator after losing a game.