Since most books have elements of many different sub-genres we allow our members to choose up to three that they think best fit each novel. The top 3 sub-genre choices from all members are displayed at the top of the novel page. These serve as the basis for our sub-genre search.

There are many different sub-genres in SF/F/H literature. We've created the lists below as an integral part of our BookTrackr™ feature. You can search for books by a specified sub-genre which makes it easy to find similar books to the ones you like or you can find new books in different sub-genres that you've not tried before.

Science Fiction Sub-Genres

Alien Invasion

The alien invasion is a common theme in science fiction stories and film, in which a technologically-superior extraterrestrial society invades Earth with the intent to replace human life, or to enslave it under a colonial system, or in some cases, to use humans as food. Alien Invasion Novels

Alternate History (SF)

Alternate history or alternative history is a subgenre of speculative fiction (or some would say of science fiction) that is set in a world in which history has diverged from history as it is generally known; more simply put, alternate history asks the question, "What if history had developed differently?" Most works in this genre are set in real historical contexts, yet feature social, geopolitical or industrial circumstances that developed differently or at a different pace from our own. While to some extent all fiction can be described as alternate history, the subgenre proper comprises fiction in which a change or point of divergence happens that causes history to diverge from our own. Alternate History (SF) Novels

Alternate/Parallel Universe

Parallel universe or alternate reality in science fiction and fantasy is a self-contained separate reality coexisting with our own. This separate reality can range in size from a small geographic region to an entire new universe, or several universes forming a multiverse. While the terms "Parallel universe" and "alternate reality" are generally synonymous and can be used interchangeably in most cases, there is sometimes an additional connotation implied with the term "alternate reality" that implies that the reality is a variant of our own. The term "parallel universe" is more general, without any connotations implying a relationship (or lack thereof) with our own universe. Alternate/Parallel Universe Novels

Apocalyptic/Post-Apocalyptic

Apocalyptic science fiction is a sub-genre of science fiction that is concerned with the end of civilization, through nuclear war, plague, or some other general disaster. Post-apocalyptic science fiction is set in a world or civilization after such a disaster. The time frame may be immediately after the catastrophe, focusing on the travails or psychology of survivors, or considerably later, often including the theme that the existence of pre-catastrophe civilization has been forgotten or mythologized. Post-apocalyptic stories often take place in an agrarian, non-technological future world, or a world where only scattered elements of technology remain. There is a considerable degree of blurring between this form of science fiction and that which deals with false utopias or dystopic societies. A work of apocalyptic or post-apocalyptic fiction might also be called a ruined Earth story, or dying Earth if the apocalypse is sufficiently dire. Apocalyptic/Post-Apocalyptic Novels

Artificial Intelligence

Artificial intelligence (AI) is a branch of computer science that deals with intelligent behavior, learning and adaptation in machines. Research in AI is concerned with producing machines to automate tasks requiring intelligent behavior. Examples include control, planning and scheduling, the ability to answer diagnostic and consumer questions, handwriting, speech, and facial recognition. As such, it has become an engineering discipline, focused on providing solutions to real life problems. AI systems are now in routine use in economics, medicine, engineering and the military, as well as being built into many common home computer software applications, traditional strategy games like computer chess and other video games. Artificial Intelligence Novels

Colonization

Colonization is the act where life forms move into a distant area where their kind is sparse or not yet existing at all and set up new settlements in the area. Colonisation applies to all life forms in a sense though it is most often used in reference to insects and humans. Insect colonisation varies from species to species though it most often involves a queen setting out from its parent colony and establishing a colony of her own at a suitable location. Human colonisation is not to be confused with colonialism or imperialism, as colonisation is a broader category, encompassing all large-scale immigrations of an established population to a 'new' location, and expansion of their civilisation into this area. This process may or may not victimise an indigenous population (depending first on whether there is any indigenous population to victimise). Colonization Novels

Cyberpunk

Cyberpunk is a sub-genre of science fiction, noted for its focus on "high tech and low life" and taking its name from the combination of cybernetics and punk. It featured advanced technology such as computers or information technology coupled with some degree of breakdown in the social order. "Classic cyberpunk characters were marginalized, alienated loners who lived on the edge of society in generally dystopic futures where daily life was impacted by rapid technological change, an ubiquitous datasphere of computerized information, and invasive modification of the human body." Cyberpunk Novels

Dying Earth

The Dying Earth subgenre is a sub-category of science fantasy which takes place at the end of Time, when the Sun slowly fades and the laws of the Universe themselves fail, with the science becoming indistinguishable from magic. More generally, the Dying Earth sub-genre encompasses science fiction works set in the far distant future in a milieu of stasis or decline. Themes of world-weariness, innocence (wounded or otherwise), idealism, entropy and the hope of renewal tend to pre-dominate. Dying Earth Novels

Dystopia

Dystopian fiction is the opposite of Utopian: creation of a nightmare world, sometimes also described as "the victory of forces of reason over forces of kindness". Dystopia Novels

First Contact

Galactic Empire

Galactic empires are a fairly common theme in science fiction. Many authors have either used a galaxy-spanning empire as background, or written about the growth or decline of such an empire. The capital of a galactic empire is frequently a core world. Some of these empires are clearly based on the Roman Empire; the Galactic Empire of Isaac Asimov's Foundation series (which inspired empires of later writers and film-makers) being an obvious example. The best known to the general public today is probably the empire from Star Wars, which was formed in turn from the Galactic Republic. Galactic Empire Novels

Generation Ship

A generation ship is a hypothetical type of starship that would travel much slower than light across great distances between stars (see interstellar travel). Since such a ship might take thousands or tens of thousands of years to reach even nearby stars, the original occupants would die during the journey, leaving their descendants to continue traveling. It is estimated that, in order to assure genetic diversity during a centuries-long trip, any generation starship would require at least 500 inhabitants (though this could also be achieved for a much smaller crew through the use of sperm banks or egg banks brought along for the journey). Additionally, the ship would have to be almost entirely self-sustaining (see Biosphere, life support) so as to provide food, air, and water for everyone on board. It must also have extraordinarily reliable systems that would not fail even over long periods of time, or alternately that could be repaired by the ship's inhabitants if they did. Generation Ship Novels

Hard SF

Hard science fiction, or hard SF, is a subgenre of science fiction characterized by an interest in scientific detail or accuracy, being the opposite of soft science fiction. It is one of several science fiction themes. There is a great deal of disagreement among readers and writers over what exactly constitutes an interest in scientific detail. Many hard SF stories focus on the natural sciences and technological developments, but many others leave technology in the background. Others contend that if the technology is left in the background it is an example of soft science fiction. Another distinction within the genre revolves around portrayals of the human condition. Some authors seek to reflect technical accuracy within an advanced, nearly utopian society in which mankind has attained victory over most human ills; others seek to portray the impact of technology on the human race with human defects still firmly in place and sometimes even magnified. Hard SF Novels

Human Development

Human development fiction predicts future capabilities evolved by mankind, such as enhanced mental or physical abilities. Human Development Novels

Immortality

Immortality (or eternal life) is the concept of existing for a potentially infinite, or indeterminate, length of time. Throughout history, many humans have had the desire to live forever. What form an unending or indefinitely-long human life would take, or whether it is even possible, has been the subject of much speculation, fantasy, and debate. Immortality Novels

Light/Humorous SF

Light/humorous science fiction may occur within any of these subgenres, or (often) spoof a subgenre. Douglas Adams' Hitchhiker's Guide to the Galaxy is one of the best-known examples of humorous science fiction. Light/Humorous SF Novels

Military SF

Military science fiction is a subgenre of science fiction where 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. In general, a detailed depiction of conflict forms the basis of most works of military science fiction. The main characters are often part of the military chain of command. Military SF Novels

Mind Uploading

In transhumanism and science fiction, mind transfer (also referred to as mind uploading or mind downloading, depending on one's point of reference), whole body emulation, or electronic transcendence refers to the hypothetical transfer of a human mind to an artificial substrate. Mind Uploading Novels

Mundane SF

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. Mundane SF Novels

Mutants

The idea of a mutant is a common trope in comic books and science fiction. The new phenotypes that appear in fictional mutations (who often have superpowers) generally go far beyond what is typically seen in biological mutants, and often result in the mutated life form exhibiting superhuman abilities. Mutants Novels

Mythic Fiction (SF)

The mythic fiction sub-genre 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. 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. Mythic Fiction (SF) Novels

Nanotechnology

Nanotechnology is the design, characterization, production and application of structures, devices and systems by controlling shape and size on the nanoscale. Eight to ten atoms span one nanometer (nm). A human hair is approximately 70,000 to 80,000 nm thick. Nanotechnology has been put to practical use for a wide range of applications, including stain resistant pants, enhanced tire reinforcement and improved suntan lotion. Nanotechnology Novels

Near-Future

Near-future science fiction takes place in the present day or in the next few decades. Elements of the 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. Near-Future Novels

Pulp

Pulp magazines (or pulp fiction; often referred to as "the pulps") were inexpensive fiction magazines. They were widely published from the 1920s through the 1950s. The term pulp fiction can also refer to mass market paperbacks since the 1950s. Pulp Novels

Robots/Androids

Biorobotics is a term that loosely covers the fields of cybernetics, bionics and even genetic engineering as a collective study. Biorobotics is often used to refer to a real subfield of robotics: studying how to make robots that emulate or simulate living biological organisms mechanically or even chemically. The term is also used in a reverse definition: making biological organisms as manipulatable and functional as robots. In the latter sense biorobotics is referred to as a theoretical discipline of comprehensive genetic engineering in which organisms are created and designed by artificial means. The creation of life from non-living matter for example, would be biorobotics. Because of its mostly theoretical status it is presently limited to science fiction; the actual field is in its infancy and is known as synthetic biology and Bionanotechnology. Robots/Androids Novels

Science-Fantasy

This sub-genre is a fusion between the two main genres. It represents works that use main elements of both to create a story that is (for example) futuristic and technical in tone, with fantastical sub-plots and characters. Arthur C. Clarke once said, "any sufficiently advanced technology is indistinguishable from magic", which might make the sub-genre easier to identify! Some would argue that there are even "sub-genres for the sub-genre" in this category, but for our purposes we will stick with the high-level definition given here! Anne McCaffrey's "Pern" novels are good examples of this sub- genre. Science-Fantasy Novels

Singularity

In futures studies, a technological singularity (often the Singularity) is a predicted future event believed to precede immense technological progress in an unprecedentedly brief time. Futurists give varying predictions as to the extent of this progress, the speed at which it occurs, and the exact cause and nature of the event itself. Singularity Novels

Slipstream

Slipstream deals with "mainstream" themes but contains a speculative element. Margaret Atwood's The Handmaid's Tale is set in a speculative future, for example, but is marketed as a mainstream novel. Slipstream Novels

Soft SF

Soft Science Fiction involves the less exact sciences, such as sociology, psychology, or anthropology. One excellent example of advanced sociology would be the science of "psychohistory" described in Asimov's Foundation series Soft SF Novels

Space Exploration

Space exploration is the physical exploration of outer space. The politics, science, and engineering behind space flight all fall under the auspices of space exploration. There are many rationales behind space exploration; among the most common are ones focusing on scientific research or the future survival of humanity. This endeavour has been to some degree a dream and goal of humanity for the past several centuries, but it was not until the development of large liquid-fueled rocket engines during the early 20th century that it really began to be seriously developed. Space Exploration Novels

Space Opera

A space opera is usually set in outer space or on a distant planet. In most cases, to keep the story fast moving, a spaceship can fly almost unlimited distances in a short time, and can turn on a dime, without the boring necessity of decelerating. The planets usually have earthlike atmospheres (Earth's moon is an exception) and exotic life forms. Aliens usually speak English, sometimes with an accent. The machinery of space opera often includes (in addition to spaceships) ray-guns, robots, and flying cars. Space opera backgrounds may vary considerably in scientific plausibility. Most space operas conveniently violate the known laws of physics by positing some form of faster-than-light travel. Many space operas diverge even more from known physical reality, and not uncommonly invoke paranormal forces, or vast powers capable of destroying whole planets, stars, or galaxies. Space Opera Novels

Steampunk

Steampunk is a sub-genre of science fiction that refers to works set in an era where steam power is still widely used — usually the 19th century, and often Victorian era England — but with technological inventions like those found in the works of H. G. Wells and Jules Verne. Steampunk contains alternate history-style elements of past technologies like dirigibles or mechanical computers combined with futuristic technologies like multi-function goggles, giant robots and ray guns. Steampunk Novels

Terraforming

Terraforming (literally, "Earth-shaping") is the theoretical process of modifying a planet, moon, or other body to a more habitable atmosphere, temperature, or ecology. It is a type of planetary engineering. The term is sometimes used broadly as a synonym for planetary engineering in general. The concepts of terraforming are rooted both in science fiction and actual science. The term was probably coined by Jack Williamson in a science-fiction story published in 1942 in Astounding Science Fiction[1], but the actual concept pre-dates this work. Olaf Stapledon's Last and First Men (1930)[2] provides an example in fiction in which Venus is modified after a long and destructive war with the original inhabitants, who naturally object to the process. Terraforming Novels

Theological

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.). 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 an exploratory medium, SF rarely takes religion at face value by simply accepting or rejecting it. 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. Also, 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. Theological Novels

Time Travel

Time travel is the concept of moving backward or forward to different points in time, in a manner analogous to moving through space. Additionally, some interpretations of time travel suggest the possibility of travel between parallel realities or universes. Time Travel Novels

Uplift

In science fiction, biological uplift is a common but by no means universal term for the act of an advanced civilization helping the development of another species by bringing a non-sapient one into sentience, or by giving a sapient one spacefaring capabilities. The best-known use of the term is in David Brin's Uplift series, which may have popularized it. Orion's Arm uses the term provolve to avoid possible copyright issues with David Brin. Uplifting also refers to the theoretical prospect of endowing non-human animals with greater capacities, including and especially increased intelligence. It is highly likely that biological uplifting would be accomplished through the application of genetic and transgenic technologies, and possibly even artificial intelligence. Uplift Novels

Utopia

Utopian fiction is the creation of an ideal world as the setting for a novel. Utopia Novels

Virtual Reality

Virtual reality (VR) is a technology which allows a user to interact with a computer-simulated environment. Most virtual reality environments are primarily visual experiences, displayed either on a computer screen or through special stereoscopic displays, but some simulations include additional sensory information, such as sound through speakers or headphones. Some advanced and experimental systems have included limited tactile information, known as force feedback. Users can interact with a virtual environment either through the use of standard input devices such as a keyboard and mouse, or through multimodal devices such as a wired glove, the Polhemus boom arm, and/or omnidirectional treadmill. The simulated environment can be similar to the real world, for example, simulations for pilot or combat training, or it can differ significantly from reality, as in VR games. Virtual Reality Novels

Weird (SF)