Science fantasy is a hybrid genre within speculative fiction that simultaneously draws upon or combines tropes and elements from both science fiction and fantasy.  In a conventional science fiction story, the world is presented as being scientifically logical; while a conventional fantasy story contains mostly supernatural and artistic elements that disregard the scientific laws of the real world. The world of science fantasy, however, is laid out to be scientifically logical and often supplied with hard science–like explanations of any supernatural elements.  
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 Science Fiction . 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. 
Distinguishing between pure science fiction and pure 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 fantastical or supernatural elements, science fantasy explicitly relies upon them to complement the scientific elements.
In explaining the intrigue of science fantasy, Carl D. Malmgren provides an intro in regards to C. S. Lewis's 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.[ citation needed ]
Ace Books published a number of books as science fantasy during the 1950s and 1960s.[ citation needed ]
The Encyclopedia of Science Fiction points out that as a genre, science fantasy "has never been clearly defined", and was most commonly used in the period 1950–1966. 
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 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. 
The Star Wars franchise has been debated as science fantasy. In 2015, George Lucas stated that "Star Wars isn't a science-fiction film, it's a fantasy film and a space opera".  
Sword and sorcery (S&S) is a subgenre of fantasy characterized by sword-wielding heroes engaged in exciting and violent adventures. Elements of romance, magic, and the supernatural are also often present. Unlike works of high fantasy, the tales, though dramatic, focus on personal battles rather than world-endangering matters. Sword and sorcery commonly overlaps with heroic fantasy.
A campaign setting is usually a fictional world which serves as a setting for a role-playing game or wargame campaign. A campaign is a series of individual adventures, and a campaign setting is the world in which such adventures and campaigns take place. Usually a campaign setting is designed for a specific game or a specific genre of game. There are numerous campaign settings available both in print and online. In addition to published campaign settings available for purchase, many game masters create their own settings, often referred to as "homebrew" settings or worlds.
Weird fiction is a subgenre of speculative fiction originating in the late 19th and early 20th centuries. Weird fiction either eschews or radically reinterprets ghosts, vampires, werewolves, and other traditional antagonists of supernatural horror fiction. Writers on the subject of weird fiction, such as China Miéville, sometimes use "the tentacle" to represent this type of writing. The tentacle is a limb-type absent from most of the monsters of European folklore and gothic fiction, but often attached to the monstrous creatures created by weird fiction writers, such as William Hope Hodgson, M. R. James, Clark Ashton Smith, and H. P. Lovecraft. Weird fiction often attempts to inspire awe as well as fear in response to its fictional creations, causing commentators like Miéville to paraphrase Goethe in saying that weird fiction evokes a sense of the numinous. Although "weird fiction" has been chiefly used as a historical description for works through the 1930s, it experienced a resurgence in the 1980s and 1990s, under the labels of New Weird and Slipstream, which continues into the 21st century.
Unknown was an American pulp fantasy fiction magazine, published from 1939 to 1943 by Street & Smith, and edited by John W. Campbell. Unknown was a companion to Street & Smith's science fiction pulp, Astounding Science Fiction, which was also edited by Campbell at the time; many authors and illustrators contributed to both magazines. The leading fantasy magazine in the 1930s was Weird Tales, which focused on shock and horror. Campbell wanted to publish a fantasy magazine with more finesse and humor than Weird Tales, and put his plans into action when Eric Frank Russell sent him the manuscript of his novel Sinister Barrier, about aliens who own the human race. Unknown's first issue appeared in March 1939; in addition to Sinister Barrier, it included H. L. Gold's "Trouble With Water", a humorous fantasy about a New Yorker who meets a water gnome. Gold's story was the first of many in Unknown to combine commonplace reality with the fantastic.
Fantasy literature is literature set in an imaginary universe, often but not always without any locations, events, or people from the real world. Magic, the supernatural and magical creatures are common in many of these imaginary worlds. Fantasy literature may be directed at both children and adults.
Supernatural fiction or supernaturalist fiction is a genre of speculative fiction that exploits or is centered on supernatural themes, often contradicting naturalist assumptions of the real world.
The New Weird is a literary genre that emerged in the 1990s through early 2000s with characteristics of weird fiction and other speculative fiction subgenres. M. John Harrison is credited with creating the term "New Weird" in the introduction to The Tain in 2002. The writers involved are mostly novelists who are considered to be part of the horror or speculative fiction genres but who often cross genre boundaries. Notable authors include K. J. Bishop, Paul Di Filippo, M. John Harrison, Jeffrey Ford, Storm Constantine, China Miéville, Alastair Reynolds, Justina Robson, Steph Swainston, Mary Gentle, Michael Cisco, Jeff VanderMeer and Conrad Williams, among others.
Elements of the supernatural and the fantastic were an element of literature from its beginning. The modern genre is distinguished from tales and folklore which contain fantastic elements, first by the acknowledged fictitious nature of the work, and second by the naming of an author. Works in which the marvels were not necessarily believed, or only half-believed, such as the European romances of chivalry and the tales of the Arabian Nights, slowly evolved into works with such traits. Authors like George MacDonald created the first explicitly fantastic works.
Weird West is a term used for the hybrid genres of fantasy Western, horror Western and science fiction Western. The term originated with DC's Weird Western Tales in 1972, but the idea is older as the genres have been blended since the 1930s, possibly earlier, in B-movie Westerns, comic books, movie serials and pulp magazines. Individually, the hybrid genres combine elements of the Western genre with those of fantasy, horror and science fiction respectively.
The literary genre of science fiction is diverse, and its exact definition remains a contested question among both scholars and devotees. This lack of consensus is reflected in debates about the genre's history, particularly over determining its exact origins. There are two broad camps of thought, one that identifies the genre's roots in early fantastical works such as the Sumerian Epic of Gilgamesh. A second approach argues that science fiction only became possible sometime between the 17th and early 19th centuries, following the scientific revolution and major discoveries in astronomy, physics, and mathematics.
Speculative poetry is a genre of poetry that focusses on fantastic, science fictional and mythological themes. It is also known as science fiction poetry or fantastic poetry. It is distinguished from other poetic genres by being categorized by its subject matter, rather than by the poetry's form. Suzette Haden Elgin defined the genre as "about a reality that is in some way different from the existing reality."
Fantastic Adventures was an American pulp fantasy and science fiction magazine, published from 1939 to 1953 by Ziff-Davis. It was initially edited by Raymond A. Palmer, who was also the editor of Amazing Stories, Ziff-Davis's other science fiction title. The first nine issues were in bedsheet format, but in June 1940 the magazine switched to a standard pulp size. It was almost cancelled at the end of 1940, but the October 1940 issue enjoyed unexpectedly good sales, helped by a strong cover by J. Allen St. John for Robert Moore Williams' Jongor of Lost Land. By May 1941 the magazine was on a regular monthly schedule. Historians of science fiction consider that Palmer was unable to maintain a consistently high standard of fiction, but Fantastic Adventures soon developed a reputation for light-hearted and whimsical stories. Much of the material was written by a small group of writers under both their own names and house names. The cover art, like those of many other pulps of the era, focused on beautiful women in melodramatic action scenes. One regular cover artist was H.W. McCauley, whose glamorous "MacGirl" covers were popular with the readers, though the emphasis on depictions of attractive and often partly clothed women did draw some objections.
There have been many attempts at defining science fiction. This is a list of definitions that have been offered by authors, editors, critics and fans over the years since science fiction became a genre. Definitions of related terms such as "science fantasy", "speculative fiction", and "fabulation" are included where they are intended as definitions of aspects of science fiction or because they illuminate related definitions—see e.g. Robert Scholes's definitions of "fabulation" and "structural fabulation" below. Some definitions of sub-types of science fiction are included, too; for example see David Ketterer's definition of "philosophically-oriented science fiction". In addition, some definitions are included that define, for example, a science fiction story, rather than science fiction itself, since these also illuminate an underlying definition of science fiction.
Science fiction studies is the common name for the academic discipline that studies and researches the history, culture, and works of science fiction and, more broadly, speculative fiction.
William Levi Crawford was an American publisher and editor.
Science-Fiction Plus was an American science fiction magazine published by Hugo Gernsback for seven issues in 1953. In 1926, Gernsback had launched Amazing Stories, the first science fiction magazine, but he had not been involved in the genre since 1936, when he sold Wonder Stories. Science-Fiction Plus was initially in slick format, meaning that it was large-size and printed on glossy paper. Gernsback had always believed in the educational power of science fiction, and he continued to advocate his views in the new magazine's editorials. The managing editor, Sam Moskowitz, had been a reader of the early pulp magazines, and published many writers who had been popular before World War II, such as Raymond Z. Gallun, Eando Binder, and Harry Bates. Combined with Gernsback's earnest editorials, the use of these early writers gave the magazine an anachronistic feel.
Fantasy is a genre of speculative fiction involving magical elements, typically set in a fictional universe and sometimes inspired by mythology and folklore. Its roots are in oral traditions, which then became fantasy literature and drama. From the twentieth century, it has expanded further into various media, including film, television, graphic novels, manga, animations and video games.
Space opera is a subgenre of science fiction that emphasizes space warfare, with use of melodramatic, risk-taking space adventures, relationships, and chivalric romance. Set mainly or entirely in outer space, it features technological and social advancements in faster-than-light travel, futuristic weapons, and sophisticated technology, on a backdrop of galactic empires and interstellar wars with fictional aliens, often in fictional galaxies. The term has no relation to opera music, but is instead a play on the terms "soap opera", a melodramatic television series, and "horse opera", which was coined during the 1930s to indicate a clichéd and formulaic Western film. Space operas emerged in the 1930s and continue to be produced in literature, film, comics, television, video games and board games.
The following outline is provided as an overview of and topical guide to fantasy:
Science-fiction and fantasy magazines began to be published in the United States in the 1920s. Stories with science-fiction themes had been appearing for decades in pulp magazines such as Argosy, but there were no magazines that specialized in a single genre until 1915, when Street & Smith, one of the major pulp publishers, brought out Detective Story Magazine. The first magazine to focus solely on fantasy and horror was Weird Tales, which was launched in 1923, and established itself as the leading weird fiction magazine over the next two decades; writers such as H.P. Lovecraft, Clark Ashton Smith and Robert E. Howard became regular contributors. In 1926 Weird Tales was joined by Amazing Stories, published by Hugo Gernsback; Amazing printed only science fiction, and no fantasy. Gernsback included a letter column in Amazing Stories, and this led to the creation of organized science-fiction fandom, as fans contacted each other using the addresses published with the letters. Gernsback wanted the fiction he printed to be scientifically accurate, and educational, as well as entertaining, but found it difficult to obtain stories that met his goals; he printed "The Moon Pool" by Abraham Merritt in 1927, despite it being completely unscientific. Gernsback lost control of Amazing Stories in 1929, but quickly started several new magazines. Wonder Stories, one of Gernsback's titles, was edited by David Lasser, who worked to improve the quality of the fiction he received. Another early competitor was Astounding Stories of Super-Science, which appeared in 1930, edited by Harry Bates, but Bates printed only the most basic adventure stories with minimal scientific content, and little of the material from his era is now remembered.