Retroactive continuity

Retroactive continuity, colloquially known as a retcon, is a literary device in fictional story telling whereby facts and events established through the narrative are adjusted, ignored, supplemented, or contradicted by a subsequently published work that recontextualizes or breaks continuity with the former. There are various motivations for applying retroactive continuity, including: To accommodate desired aspects of sequels or derivative works which would otherwise be ruled out. To respond to negative fan reception of previous stories. To correct and overcome errors or problems identified in the prior work since its publication.