In his 1983 collection Unicorn Variations, Zelazny explained the story's origin: he had been approached by Gardner Dozois, who was soliciting content for an anthology of stories about unicorns. Subsequently, he was approached by another editor, who was soliciting content for an anthology of stories set in bars. When Zelazny told George R. R. Martin of these encounters, Martin said that Fred Saberhagen was soliciting content for an anthology of stories about chess; he then jokingly suggested that Zelazny write a story about chess and unicorns in a bar, so that he could sell the story to all three anthologies.[4]
Zelazny went on to do exactly that and subsequently won a Hugo Award for the story. The game described is Halprin v. Pillsbury in Munich, 1900.