These ludic analogies are not merely present to elucidate the method of the detective or the psychology of the villain, however.
In Poe’s ‘The Murders in the Rue Morgue’ (1841), too, right at the outset, Dupin offers a lengthy disquisition comparing chess with draughts as a way of illustrating the ‘higher powers of the reflective intellect’ (which he counterintuitively believed were best characterised by the latter). Edgar Allan Poe, for example, makes reference to the marble game ‘even-and-odd’ in ‘The Purloined Letter’, and in the same story his detective Dupin uses the example of a map puzzle game to explain the success of his ‘hiding-in-plain-sight’ tactic. Parlour games are often used as analogies in detective stories.
You have already learned about the importance of puzzles and riddles to the genre as a whole. While much has been written about fairness, it is arguably a less important ingredient in crime fiction than the concept of ‘play’ itself. 3.1 Mahjong: the function of the clue–puzzle narrative