genre of speculative fiction, where one or more historical events occur differently
Alternate history (also alternative history, althist, AH) is a genre of speculative fiction of stories in which one or more historical events occur and are resolved differently than in real life. As conjecture based upon historical fact, alternate history stories propose What if? scenarios about crucial events in human history, and present outcomes very different from the historical record. Alternate history also is a subgenre of literary fiction, science fiction, and historical fiction; as literature, alternate history uses the tropes of the genre to answer the What if? speculations of the story.
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