- Science fiction is a literary genre that explores futuristic and/or alien concepts grounded in scientific principles, technology, or discoveries.
- Science fiction often focuses on how science or technology affects individuals, societies, or the natural world.
- Common sci-fi themes include space exploration, time travel, artificial intelligence, and the consequences of technological advancements.
- Unlike fantasy, which incorporates magical or supernatural elements, sci-fi usually strives for scientific plausibility, even as it speculates about things that don’t exist in our world.
The rest of this article explains (1) what science fiction is, (2) common characteristics of the genre, and (3) how it’s different from other genres of speculative fiction.
What Is Science Fiction?
So, what is science fiction?
The Merriam-Webster dictionary defines it as “fiction dealing principally with the impact of actual or imagined science on society or individuals or having a scientific factor as an essential orienting component.”
Of all the definitions I reviewed when creating this guide, that one is the most complete. It might be improved by changing “science” to say “science or technology.” But other than that, this definition does a solid job of explaining what science fiction is.
As a genre of speculative fiction, sci-fi explores imaginative and futuristic concepts, often involving advanced technology, space exploration, and the impact of science on society.
Here’s another way to think of it:
If the scientific or technological element can be removed from a story—and the story still works—then it’s probably not science fiction. It’s simply a story that includes scientific elements but doesn’t need them.
On the other, if removing the scientific aspects caused the entire story to collapse or fall apart, then it probably meets the definition of science fiction.
Let’s use the 1990 sci-fi novel Jurassic Park as an example, since most of us are at least familiar with that story. In that novel (and subsequent movie), genetic researchers figure out how to bring dinosaurs to life by using a proprietary DNA extraction and cloning process.
The scientific components — cloning and DNA — form the framework for that story. If you were to remove those elements, the story would no longer work. The entire plot would collapse. There would be no resurrected dinosaurs, no dangerous theme park, no survival scenario, etc.
As a story, Jurassic Park “works” because of the plausible scientific components introduced in the beginning. That’s what makes it science fiction—and that’s what defines the genre.
Key Characteristics of Sci-Fi Stories
Elsewhere on this site, you can find a detailed look at the characteristics of science fiction. Here’s a quick overview of the genre’s three primary features:
- It speculates. Science fiction is grounded in scientific or technological plausibility, but it explores concepts that might be true in some other time or place. It often includes futuristic technology, space travel, alien life, and other speculative elements.
- It requires science or tech. Sci-fi stories include scientific and technological concepts that are fundamental to the story and inseparable from it (as in the Jurassic Park example above). These stories cannot survive without the science; it’s what holds them together.
- It warns of consequences. Sometimes, science fiction delivers good old-fashioned fun and little else. But it can also serve a deeper purpose. It invites us to consider the consequences of our actions, within the context of scientific or technological development. Science fiction does this by showing us the consequences, not by preaching about them.
These characteristics help to set science fiction apart from other genres and make it a unique and thought-provoking form of storytelling.
How It’s Different from Other Genres
Science fiction differs from other genres in several ways. The main distinction relates to the inclusion of scientific or technological elements, as we’ve already discussed.
If a story revolves around some important aspect of science or tech, then it meets the definition of science fiction. But if it doesn’t—it doesn’t.
Consider the fantasy genre for a moment. Science fiction and fantasy are often lumped together as one big category of fiction. The Magazine of Fantasy and Science Fiction, for example, has been publishing these two genres together for more than 70 years.
Yet there are some key distinctions between these often-combined genres. The main difference is that sci-fi deals with speculative and often futuristic concepts that are rooted in science and technology, while fantasy explores imaginary worlds, magic, and supernatural elements.
Science fiction differs from other genres as well, and for the reasons stated above.
Ultimately, it comes down to the story’s focus and emphasis. Science fiction stories are typically more focused on the exploration of scientific ideas and the potential consequences of technological advancement.
Some stories contain scientific elements but aren’t necessarily built around those elements. So they’re not science fiction; they’re stories that include some degree of science that’s not central to the plot.
Remember the “test” from earlier? If you can remove the scientific component and the story still works, then it’s not science fiction. In sci-fi, the science or technology is central to the plot. It’s the thread that connects. The plot relies on those elements to reach the ending.
Popular Subgenres of Science Fiction
Now that we know what science fiction is, let’s talk about how it’s classified. What are the different subgenres of sci-fi? What kinds of stories fall under this broad umbrella?
The science fiction genre tends to defy categorization. It pushes the boundaries of literature, breaking rules and smashing norms along the way.
Even so, a little classification can be useful. It helps us zero in on the types of stories we enjoy the most, so we can explore similar works. With that in mind, here are ten of the most popular subgenres of science fiction:
- Alien Invasion: Stories about extraterrestrials arriving on Earth, often with hostile intentions.
- Alternate Worlds / Parallel Universe / Multiverse: Stories set in a world other than our own, often one that is very different from ours.
- Androids, Robots, and Artificial Intelligence (AI): Stories about machines that are capable of thinking and acting like humans.
- Apocalyptic and Post-Apocalyptic: Stories set during or after a cataclysmic event that has destroyed or damaged civilization, often depicting humanity’s struggle to survive.
- Cyberpunk: Stories set in a near-future where technology has advanced dramatically, juxtaposed with societal collapse, dystopia or decay.
- Dystopian: Stories set in a future or alternate world where society is oppressive, undesirable and totalitarian. (They can be a subgenre of sci-fi or fall under mainstream fiction, depending on the story’s theme and premise.)
- Military Science Fiction: Stories that occur in a future where warfare has become increasingly sophisticated, often involving battles between humans and aliens.
- Space Opera: Stories set in space, typically featuring grand adventures, epic battles, and exotic worlds.
- Sci-Fi Horror: Stories that combine elements of science fiction and horror.
- Steampunk: Stories set in a Victorian-era kind of setting with advanced technology that is often powered by steam or clockwork.
Learn more about the different subgenres of sci-fi
