Science fantasy is a mixed genre within the umbrella of speculative fiction which simultaneously draws upon or combines tropes and elements from both science fiction and fantasy. In a science-fiction story, the world is scientifically possible, while a science-fantasy world contains elements which violate the scientific laws of the real world. Nevertheless the world of science fantasy is logical and often is supplied with science-like explanations of these violations.
During the Golden Age of Science Fiction, the fanciful science-fantasy stories were seen in sharp contrast to the terse, scientifically plausible material that came to dominate mainstream science fiction typified by the magazine Astounding Stories. Although at this time, science-fantasy stories were often relegated to the status of children's entertainment, their freedom of imagination and romance proved to be an early major influence on the "New Wave" writers of the 1960s, who became exasperated by the limitations of "hard" SF.
Eric R. Williams lists the following "microgenres" which can belong to science fantasy: Discovery, Dying Earth, ET Relations, Mad Scientist, Space Opera, Sword and Planet. Carl D. Malmgren classifies science fantasy by the type of the violation of science and distinguishes the following main types: the time-loop motif, the alternate-present world, the counterscientific world, and the hybridized world.
Distinguishing between science fiction and fantasy, Rod Serling claimed that the former was "the improbable made possible" while the latter was "the impossible made probable". As a combination of the two, science fantasy gives a scientific veneer of realism to things that simply could not happen in the real world under any circumstances. Where science fiction does not permit the existence of fantasy or supernatural elements, science fantasy explicitly relies upon them.
In explaining the intrigue of science fantasy Carl D. Malmgren provides an intro in regards to C.S. Lewis speculation on the emotional needs at work in the subgenre: "In the counternatural worlds of science fantasy, the imaginary and the actual, the magical and the prosaic, the mythical and the scientific, meet and interanimate. In so doing, these worlds inspire us with new sensations and experiences, with [quoting C.S. Lewis] 'such beauty, awe, or terror as the actual world does not supply', with the stuff of desires, dreams, and dread."
The label first came into wide use after many science fantasy stories were published in the American pulp magazines, such as Robert A. Heinlein's Magic, Inc., L. Ron Hubbard's Slaves of Sleep, and Fletcher Pratt and L. Sprague de Camp's Harold Shea series. All were relatively rationalistic stories published in John W. Campbell, Jr.'s Unknown magazine. These were a deliberate attempt to apply the techniques and attitudes of science fiction to traditional fantasy subjects. The Magazine of Fantasy and Science Fiction published, among other things, all but the last of the Operation series, by Poul Anderson.
Henry Kuttner and C. L. Moore published novels in Startling Stories, alone and together, which were far more romantic. These were closely related to the work that they and others were doing for outlets like Weird Tales, such as Moore's Northwest Smith stories.
The Star Trek franchise created by Gene Roddenberry is sometimes cited as an example of science fantasy. Writer James F. Broderick describes Star Trek as science fantasy because it includes semi-futuristic as well as supernatural/fantasy elements such as The Q. According to the late iconic science fiction author, Arthur C. Clarke, many purists argue that Star Trek is science fantasy rather than science fiction because of its scientifically improbable elements, which he partially agreed with.
- Malmgren, Carl D. (1988). "Towards a Definition of Science Fantasy (Vers une définition de la fantaisie scientifique)". Science Fiction Studies. 15 (3): 259–281. JSTOR 4239897.
- Eric R. Williams, The Screenwriters Taxonomy: A Collaborative Approach to Creative Storytelling, p. 121
- Moorcock, Michael (13 June 2002). "Queen of the Martian Mysteries: An Appreciation of Leigh Brackett". Fantastic Metropolis. Archived from the original on 18 February 2012. Retrieved 7 July 2017.
- "The Fugitive". The Twilight Zone. Season 3. Episode 25. March 9, 1962. CBS.
- Nussbaum, Abigail (April 2, 2015). "Science Fantasy". In Nicholas, Peter (ed.). The Encyclopedia of Science Fiction. Retrieved May 25, 2017.
- Broderick, James F. (2006). "Chapter Sixteen: Fantasy Versus Reality". The Literary Galaxy of Star Trek: An Analysis of References and Themes in the Television Series and Films. Jefferson, N.C.: McFarland & Co. pp. 135–144. ISBN 9780786425716. OCLC 475148033.
- Clarke, Arthur C. (October 2006). "Forty Years of Star Trek". Locus. No. 549 (Vol. 57, No. 4). Retrieved May 25, 2017 – via the website Star Trek: Of Gods and Men.