Stories about the discoveries of lost civilizations, lost worlds or lost cultures
These stories center around actual mathmatical concepts. Douglas Hofstadter's scholarly tome Godel, Escher, Bach uses short fictional stories as illustrations. Catherine Asaro's novella "The Spacetime Pool" features life-and-death math puzzles. In cinema, the 1998 feature film Pi is an excellent example of this subgenre. The plot evolves around a mathematical genius, Maximillian Cohen, who theorizes that everything in nature can be understood through numbers. Knowing starring Nicholas Cage is another film example.
MEDIA TIE-IN SCI-FI
Media tie-in (game-based, Star Trek novels, etc.) is a self-explanatory subgenre. Whether originally a book, a video game, or a screenplay, the novel versions build upon these tale's on-screen popularity. These stories must conform to strict rules, like not allowing the main characters to change very much, so that they'll continue to match the series' canon.
Often these books have a huge marketing budget, and they tend to dominate chain bookstore shelves. A big hit at the box office is the Resident Evil films adapted from a video game about a special military unit who fights a powerful, out-of-control supercomputer and hundreds of scientists who have mutated into flesh-eating creatures after a laboratory accident.
Concerned less with technology and space opera and more with sociological speculation about human society
Military science fiction looks at combat in future locations (space, another planet), against a range of opponents (modified humans, aliens, machines), with futuristic, high-tech weaponry (including genetically modified soldiers). Stories in this sub-genre may revel in warfare or suggest anti-war themes. In some stories, interstellar or interplanetary conflict and its armed solution (war) make up the main or partial backdrop of the story.
Such war is usually shown from the point of view of a soldier and / or the main characters are often part of the military chain of command. Very popular in cinema is Paul Verhoeven's film adaption of Robert Heinlein's Starship Troopers. The military system and its characters of this film was a large part of the dramatization.
Literature examples include David Drake's Hammer's Slammers series, which explores both the heroism and the carnage of warfare, and Orson Scott Card's Ender Wiggin series, starting with Ender's Game, is a military SF novel with a strong emphasis on sociological issues, and is one of the seminal series in this sub-genre. Jerry Pournelle’s John Christian Falkenberg novels, Keith Laumer’s Bolo novels, Joe Haldman's novel The Forever War, and David Feintuch's "Hope" novels are other examples.
Mundane SF focuses on stories set on or near the Earth, with a believable use of technology and science as it exists at the time the story is written. It features near-future stories, without any improbable technologies, or interplanetary settings, at least beyond what known spacecraft can reach. A possible film example would be Gravity. While it's scientific accuracy has been the subject of hot debate, the film overall is based on familiar technologies and is set near Earth.
Refers to titles rooted in fables or mythology
The works are, ultimately, inspired by, or that in some way draws from the tropes, themes and symbolism of myth, folklore, and fairy tales. Some stories depict aliens and/or humans using high-tech means to recreate mythological settings, and the "magical powers" of the ancient gods. These could be pantheon-based characterisations, or retellings of famous mythological journeys in SF/ F settings. Neil Gaiman and John Crowley are masters of this sub-genre.
Another example, Dan Simmons' novel Ilium brings an idyllic Mount Olympus and the bloody Trojan War to Mars--sort of. In Roger Zelazney's classic novel Lord of Light, the main characters employ technology to cast themselves as deities from the mythology of India. Syfy's award winning series Battlestar Galactica is steeped with Greek mythology.
Worshiping Greek Gods, some of the names of the 12 human colonies include Caprica, Picon, Sagittaron, Tauron, and Vigron. These survivors are on a quest to find the mythical 13th colony - Earth. Other examples from TV is the Star Trek original-series episode "Who Mourns for Adonais?" and the Stargate series which Asgard and Thor are woven into the ongoing plot.
Nanotechnology is the design, characterization, production and application of structures, devices and systems by controlling shape and size on the nanoscale. Nanotechnology has been put to practical use for a wide range of applications, including stain resistant pants, enhanced tire reinforcement and improved suntan lotion. Another description of this subgenre is Nanopunk, which has been regarded as one of cyberpunk's many offshoots.
It explores the effects of advanced nanotechnology on humanity. Linda Nagata's novel Tech Heaven is the principal example, while Michael Crichton's novel Prey introduced the concept to the mainstream. The 1963 and 1995 television series The Outer Limits not only contained episodes as examples of this subgenre, but the series could fill the bill for many of the subgenres featured in this article.
One such episode is The New Breed, which is a fine example of Nanotech Sci-Fi. In this episode, Dr. Stephen Ledbetter makes a technological and medical breakthrough when he creates a type of tiny machine, known as nanobots, capable of curing any disease or imperfections in the human body.
Takes place in the present day or in the next few decades
Elements of the Near-future science fiction setting should be familiar to the reader, and the technology may be current or in development. Stories about nanotechnology or genetics, such as Greg Bear's Blood Music, often fall into this category.
NEW WAVE SCI-FI
Characterised by a high degree of experimentation, both in form and in content
New Wave SF was a movement and a literary style, beginning in England and spreading to the USA and beyond. Michael Moorcock launched the trend in 1964, and Harlan Ellison's two "Dangerous Visions" anthologies are now viewed as its high point. This subgenre rose and fell with western society's embrace of 1960s radicalism, and desire to 'shock the bourgeoisie.' (Echoes of the movement have affected SF, and literature in general, ever since.)
This subgenre encompasses a wide reach, and yet remains unusual. It features blue collar protagonists, on Earth or in recognizable circumstances, rather than hifalutin scientists or astronauts. The hero of John DeChancie's novel Starrigger is a truck driver. Piers Anthony's novel Hard Sell realistically depicts several workaday occupations.
Most other examples are short stories.
n cinema, the 2010 feature film Repo Men centers around two repo collector's set in the near future. Rather than repossessing cars, the blue collar hunters go after clients who failed to pay for their organ replacements.
OTHER WORLDS SCI-FI
Totally fictional worlds/universes feature in these stories. Frank Herbert's classic "Dune" featured perhaps the most popular 'other world' in science fiction history. Dune was adapted to feature film with David Lynch's 1984 box office dud and Syfy's pair of miniseries including Children of Dune. Anne McCaffrey also created a hugely popular fictional world, "Pern", populated by telepathic dragons.
PARALLEL UNIVERSES/WORLDS SCI-FI
Events occuring in our world being run on a parallel with an alternate, parallel dimension/world/universe
Parallel Universe stories deal with the quantum concept that every choice or decision happens somewhere. This separate reality can range in size from a small geographic region to an entire new universe, or several universes forming a multiverse. The other universe(s) can be very strange, with differing physical laws, or (number of) spatial dimensions.
The television series Fringe and Sliders are model examples of this subgenre. With the latter, the real nature of the show changed throughout the seasons. The first two seasons explored what would have happened, for example, if America had been conquered by the Soviet Union or if penicillin had not been invented.
The third season became far more action-oriented, even going so far as to devolve into riffs on major genre feature films (including Tremors, Species, and The Island of Dr. Moreau). Literature examples include Steven Gould’s Wildside and John Cramer’s Einstein’s Bridge and Isaac Asimov's novel The Gods Themselves, with its utterly different intelligent aliens. Greg Egan's novel Diaspora features mind-bending descriptions of a four-dimensional universe.
SUBSET: MULTIVERSE SCI-FI
Multiverse stories feature multiple universes, often with differing versions of our familiar Earth. This sub-set assumes that some variant of the Multiverse/Landscape cosmological theory is true. There is always some way (whether secret or common) to travel between the universes, or at least to communicate. Michael Kube-McDowell's novel Alternaties is a fine example. Jet Li's The One would be a good film example.
SUBSET: PLANES OF EXISTENCE SCI-FI
This subgenre resembles the Multiverse category. In this case, the other planes are often 'psychic' or 'spiritual' in nature, and are reachable by altering one's state of awareness. The novel India's Story, by Kathlyn S. Starbuck, depicts its young heroine India experiencing multiple states of consciousness via meditation, drugs, etc. Another example is Howard Hendrix's novel Standing Wave. (In most such tales, this goes beyond passive experience, into 'granting' the characters special powers.)
A film example of the Planes of Existence sub-set could be Altered States starring William Hurt, which explores the concept that other states of consciousness are as real as our waking states. Hurt's character begins experimenting with sensory-deprivation using a flotation tank, and his mind experiments cause him to experience actual, physical biological devolution.
Pastoral or Small Town SF takes place in that sort of setting. (Most SF is urban, at least when taking place on Earth.) Clifford Simak's classic novel Way Station is set entirely in rural Wisconson, while the heroine of Kay Kenyon's novel Leap Point is a small-town lass. The television series Jericho would fit this subgenre with the premise set in a small town. Jericho is an American series that centers on the residents of the fictional town of Jericho, Kansas in the aftermath of nuclear attacks on 23 major cities in the contiguous United States.
Progenitive SF is a small subgenre, which features humans and/or aliens who create science fiction of their own. One example is Vernor Vinge's novel Grimm's World, in which seagoing humans on another planet operate a respected science fiction magazine. "The Garden: A Hwarhath Science Fiction Romance," by Eleanor Arnason, is a short SF story told by aliens. In the Star Trek: DS9 TV episode "Far Beyond the Stars," Sisko is shown as a SF author who struggles with civil rights and inequality when he writes the story of Captain Benjamin Sisko, a black commander of a futuristic space station.
SUBSET: RECURSIVE SCI-FI
Recursive SF is comprised of stories that include direct references to the SF genre, and/or SF authors. A mind-bending example is the novel Venus on the Half Shell, "written" by Kilgore Trout, a pseudonym of Philip Jose Farmer. Trout is actually a fictional SF writer created by author Kurt Vonnegut. The protagonist makes frequent mention of his own favorite writer, a galactically-famous SF author. (Venus's first edition does not mention Farmer at all) Another example is HG Stratmann's short story "Wilderness Were Paradise Enow," which mentions plenty of SF-genre trivia.
Also known as Retro Sci-Fi or Retro-Futurism
Pulp SF is another descriptive category. The old SF magazines were one of many varieties of 'pulp fiction' literature, with a distinct style and format. Usually their cover art was garish, featuring brutish monsters, heroic spacemen, and scantily-clad women in distress. "Amazing Stories" was perhaps its best-known publication. (This subgenre has been revived again and again over the decades.)
An idea example in film would be Sky Captain and the World of Tomorrow, though it is a modern film, it pays homage to the eras-gone-by subgenre. The film is set in an alternative 1939 and follows the adventures of Polly Perkins (Gwyneth Paltrow) and Joe Sullivan (Jude Law) as they track down the mysterious "Dr. Totenkopf" who is seeking to build the 'World of Tomorrow'. Retro-futurism also celebrates the 'pulp' SF stories of the past. Most of these depictions are in comic books, and revive the garish cover art and 'fifties' style of the past.
Science Fiction or Fantasy about religion
Futuristic stories containing a distinct religious overtone or message, which gives meaning and motivation to their lives, although this isn't always explored in much depth. Since the genre deals explicitly with humanity's understanding of itself in the face of great technological and social change, in a certain sense most SF grapples with questions of a spiritual or religious nature.
Like any form of literature, SF can be used both to denounce and promote religious ideologies, and SF authors' opinions on the subject of religion are as diverse as their writing. As with any topic in SF, when religious themes are present they tend to be investigated very deeply. The reader is invited to step outside the conventional understanding of the subject and consider wider possibilities. As an exploratory medium, SF rarely takes religion at face value by simply accepting or rejecting it.
A few subgenre stories focus on other human faiths, whether current, in the future, or via time travel. In the feature film The Book of Eli, the plot centers around the last known Bible, set in a post-apocalyptic background. The main characters in John Wyndham's classic "The Chrysalids" are ruled by their religious beliefs - and are also castigated by the very same belief system. Kay Kenyon's well-thought-out novel The Braided World describes a strange alien priesthood (and biology), which the human visitors must struggle to understand.
SUB-SET: CHRISTIAN SCI-FI
Stories which features an explicitly Christian protagonist. Anthony Boucher's short story "The Quest for St. Aquin," and the novels of Kathy Tyers, are good examples. (Such tales are common enough to have their own subgenre, yet they're unusual in the SF genre, especially compared to the English-speaking Christian population. The reasons are open to debate.)
SUB-SET: CLERICAL SCI-FI
Clerical subgenre tales involve an organized priesthood, such as a religious order, of any human or alien religion. Set on Earth, Walter Miller's novel A Canticle for Leibowitz chronicles one sincere and long-lived order. Frank Herbert's Bene Gesserit (in his "Dune" franchise) dominates human history, yet without profound expressions of individual faith.
SUB-SET: HINDU SCI-FI:
Hindu tales feature character(s) of that faith. (India has a growing native-languages SF market, however very little has been translated into English.)
SUB-SET: ISLAMIC SCI-FI
Islamic tales center upon characters, and/or entire societies, of that faith. Donald Moffitt's novel A Gathering of Stars features an interstellar Muslim civilization, while in Nancy Kress's novel An Alien Light the derivation is more subtle. Ahmed Khan's recent anthology A Mosque Among the Stars has a fine variety of stories.
SUB-SET: JEWISH SCI-FI
Jewish SF features characters of that faith. WR Yates's novel Diasporah is set in a huge orbital colony which has replaced a destroyed Israel.
SUB-SET: THEOLOGICAL SCI-FI
Theological works often present explanations or commentary on religion and religious ideas. These vary from simple refutations of religion as primitive or unscientific, to creative explanations and new insights into religious experiences and beliefs (e.g. Gods as aliens, prophets as time travelers, metaphysical or prophetic vision gained through technological means, etc.).
RESTORED EDEN SCI-FI
Restored Eden tales are set in the mid-to-far future, here on Earth. In this subgenre most of humanity has gone on to other worlds, and the Earth has healed (all or in part, and naturally or with subtle help) into a renewed paradise. The Planet of the Apes film franchise could fall within this category in some ways.
Granted there is a different Earth primate that is the dominate species, but they created a more holistic style of life living in a forest/jungle type enviroment with little or no technology. Arthur C. Clarke's novel Against the Fall of Night decribes the technological redoubt of Diaspar and the natural haven of Lys. Clifford Simak's novel City populates the wildlands of a future Earth with speaking dogs and intelligent ants.
Fiction which has elements of both the science fiction and romance genres
Planetary Romance is an interstitial subgenre that shades into the vast Romance genre. In this case, the love story is embedded in futuristic (or fantastical) technology, and the striving lovers can be separated by more than Earthly distances. Edgar Rice Burroughs' "Barsoom" series (and Disney's feature film John Carter of Mars) features luscious Martian princesses, while Andrew M. Greeley's novel Final Planet does a good job of fusing these often disparate literary styles.