Speculative fiction is an umbrella genre encompassing fiction with certain elements that do not exist in the real world, often in the context of supernatural, futuristic or other imaginative themes. This includes, but is not limited to, science fiction, fantasy, superhero fiction, horror, utopian and dystopian fiction, supernatural fiction as well as combinations thereof (e.g. science fantasy).
Speculative fiction allow the authors great freedom to more or less subtly insert their own views on various issues, often without the need for more detailed supporting arguments and evidence needed in non-fiction. The political views expressed have often reflected the general cultural trends, thus previously often being more politically incorrect on various issues.
Today, its most influential form is as movies and television series, which include many popular ones.