How to Write Science Fiction

As you know from my how to write fantasy blog, I’m pretty picky (read: pretentious) about the science fiction I read. Remembrance of the Earth’s Past trilogy is one of the favourite books of all time. In spite of the many, many flaws in the book, I read the entire series every December.

I think the reason I’ve always been drawn to science fiction is because I’ve always been interested in physics. Science fiction as a genre is more than a simple prediction of the future (and we have plenty of bad sci-fis to prove this). It follows a fundamental question: “what if” and sci-fi authors follow that thread to its most honest and logical conclusion.  

I think the sci-fi genre serves as a mirror to our own world. Sure, it uses futuristic or alternative settings but what it does at its core is explore current social issues, human nature, and the ethics of technological advancement. The story can be set on a distant planet in a galaxy far, far away, or in a slightly altered version of the present, but what it explores is a “journey into the unknown” trope which frankly, I love.

This guide will explore how to write a science fiction story that respects reader’s intelligence, balances scientific plausibility with nuance, and create worlds that feel as real as our own. So, let’s get started.

Understanding the Genre

Before you write a science fiction book, you need to understand the scale of this genre and where your story idea fits. There are lots of subgenres within science fiction and knowing where your story lands will make your job very easy.

Hard Sci-Fi (Scientific Laws and Facts)

Hard science fiction utilises concrete scientific details, such as physics, biology, and chemistry. In these stories, science is central, and the technology described is either already in existence or hypothesized as a future possibility. 

Authors like Andy Weir in The Martian exemplify this approach, where every problem is solved through rigorous, plausible engineering. Writing in this niche requires a commitment to accuracy, as readers expect the technology to follow the established physical laws.

Soft Sci-Fi (Philosophical and Social Focus)

Soft science fiction shifts the focus from the “hard” sciences to the social sciences. Books of these genres explore psychological, political, economic, or anthropological themes. While technology is still present, the story is more concerned with how technology affects human relationships and society. 

Classics such as Ursula K. Le Guin’s The Left Hand of Darkness use speculative settings to examine gender and power dynamics rather than the technical specifications of warp drives.

Science Fantasy (Blending Magic and Tech)

Science fantasy exists on the furthest end of the soft scale. It blends the tropes of science fiction, such as starships and robots, with elements that are essentially magical or supernatural. In this subgenre, science serves as a mystical device that is never fully explained, behaving more like a traditional magic system. 

Star Wars is a primary example, where knights wield laser swords and tap into a mystical Force within a high-tech galactic setting.

Subgenres (Space Opera, Dystopian, Cyberpunk)

The genre is further divided into numerous specialized categories. Space opera focuses on grand-scale adventures in outer space, often involving intergalactic battles and complex politics, like Frank Herbert’s Dune. 

Dystopian fiction explores the breakdown of society or the rise of totalitarian control, often serving as a warning about current trends. Cyberpunk juxtaposes high tech and low life, examining the impact of advanced computer technology and cybernetics on a decaying urban society.

If you’re interested in learning more about dystopian fiction, check out my guide: How to Write Dystopian Fiction.

The Foundational Premise

Every compelling science fiction story begins with a strong foundation—a unique idea that challenges our understanding of reality.

The “What If?” Question

The core behind sci-fi is the “What If?” question. This acts as a thought experiment, such as: “What if we could clone dinosaurs?” or “What if society had no concept of gender?” To find your own, look at current technological trends, social justice issues, or historical events, and imagine one major change that ripples through the world.

Speculative Exploration

Once you have your question, you have to follow the consequences. Speculative fiction isn’t just about new technology, but how that technology transforms humanity. If humans could live for 500 years, how would that change the legal system, marriage, or the economy?. The best stories explore these second and third-order consequences with unflinching honesty.

The Human Core (Love, Loss, Tragedy)

Despite its out of this world setting, sci-fi always maintains a human core.The best stories in this genre ultimately always tell universal human stories of love, loss, ambition, and tragedy. 

If you remove the technical details, the story is still about a character searching for a family, saving their home, or struggling with their own identity.

Identifying the “Novum’

A key concept in defining sci-fi is the novum. This term was coined by critic Darko Suvin to describe the one novel insertion into an otherwise normal situation that transforms your story into the unfamiliar. It is the specific scientific or technological discovery that distinguishes your fictional world from reality. Identifying your novum early helps keep the speculation focused and grounded.The Foundational Premise

Every compelling science fiction story begins with a strong foundation—a unique idea that challenges our understanding of reality.

The “What If?” Question

The core behind sci-fi is the “What If?” question. This acts as a thought experiment, such as: “What if we could clone dinosaurs?” or “What if society had no concept of gender?” To find your own, look at current technological trends, social justice issues, or historical events, and imagine one major change that ripples through the world.

Speculative Exploration

Once you have your question, you have to follow the consequences. Speculative fiction isn’t just about new technology, but how that technology transforms humanity. If humans could live for 500 years, how would that change the legal system, marriage, or the economy?. The best stories explore these second and third-order consequences with unflinching honesty.

The Human Core (Love, Loss, Tragedy)

Despite its out of this world setting, sci-fi always maintains a human core.The best stories in this genre ultimately always tell universal human stories of love, loss, ambition, and tragedy. 

If you remove the technical details, the story is still about a character searching for a family, saving their home, or struggling with their own identity.

Identifying the “Novum’

A key concept in defining sci-fi is the novum—a term coined by critic Darko Suvin to describe the one novel insertion into an otherwise normal situation that brings about a transformative encounter with the unfamiliar. It is the specific scientific or technological discovery that distinguishes your fictional world from reality. Identifying your novum early helps keep the speculation focused and grounded.

Worldbuilding Techniques

Worldbuilding is one of the most important aspects  of this genre. It’s also a very daunting task for science fiction writers. After all, there’s a lot of research that goes into this, a lot of following the logic, following things to their end conclusion. Luckily, worldbuilding techniques themselves transcend genres and I’ve written a guide on the topic.

If you’re interested, check out my guide: On Worldbuilding: A Comprehensive Guide.

It’s a long one and I’d recommend reading it in your free time. For now, I’ve included a bunch of stuff you can’t ignore when doing sci-fi worldbuilding.

Internal Consistency and Fixed Rules

The most important rule of worldbuilding is internal consistency—regardless of genre. But in sci-fi, this is the rule.

Your world must obey its own laws of physics and logic, even if those laws are different from ours. If you establish that your technology relies on solar power, it cannot suddenly work in the dark just to save a character. These fixed rules create narrative tension; without these limitations, the stakes disappear.

Immersion Anchors

To make an unfamiliar world feel real, you have to use immersion anchors. These are small, specific details that build the reader’s trust in your worldbuilding. 

Describing how a character eats, their daily rituals, or the specific mechanics of a common piece of technology makes the setting tangible. These anchors allow the reader to fill in the gaps of the world with their own imagination.

Culture, Society, and Power Structures

Worldbuilding also includes the social and cultural landscape. Consider who the power holders are and how they maintain their status. This can be through military force, economic control, or technological monopoly. 

Think about the history of your society: what past wars or uprisings led to the current cultural norms?

History and Background of the World

Your world should feel like it has existed long before the story began and will continue long after it ends. This involves creating a backstory that informs the present. For example, a city might bear the physical scars of a previous android uprising. Or, characters might use slang that reflects ancient historical events.

Physical Setting

You should know what your world looks like as well as you know your own home. You need to be crystal clear on the environment—the color of the sky, the types of local plants, the level of gravity—so that you don’t accidentally create plot holes. If you are creating an alien planet, use research into real environments (like deserts or jungles) and then exaggerate those features for dramatic effect.

Character Development in Science Fiction

Characters are extremely important in science fiction. One of the pitfalls of the Three-Body Problem is that human characters were always underdeveloped to the point of caricatures.  Once you’ve got your magnificent world, you’ve got to have characters to drive to.

Relatable Protagonists

In a world filled with alien technology and strange planets, a relatable protagonist keeps the reader grounded. Even if they are superhuman or an alien, they should possess relatable human wants, needs, and fears. Readers might not know what it’s like to pilot a starship, but they understand the drive to protect a family or the feeling of being an outsider.

To learn more about how to write good protagonists, check out my guide: On Writing Protagonists: How to Write Great Main Characters.

Internal Contradictions and Dimensions

A multi-dimensional character is often defined by their internal contradictions. A character might be a hero who has committed atrocities, or a messianic figure who feels like a fraud. These internal conflicts drive the plot as the character struggles to reconcile their disparate identities.

Complex Antagonists

The best antagonists are not just evil for the sake of it; they are often the heroes of their own stories. A compelling villain should be objectively virtuous in some capacity. Perhaps they possess great personal courage, charisma, or an overriding sense of justice, even if that justice is warped. Often, the threat they pose to the protagonist is philosophical, forcing the hero to defend their core beliefs.

If you want to develop better antagonists, check out my guide: On Writing Villains: How to Write Complex, Compelling Antagonists.

Authentic Motivations and Growth

Characters must move the story forward as agents of their own destiny, not as puppets of the plot. Their growth should be an authentic reaction to the challenges of the speculative world. Ask yourself why this specific character is the only one who can fight this specific battle in this world.

Plotting and Structure

While sci-fi allows for infinite possibilities, a story still requires a logical sequence of events to keep the reader invested.

Essential Outlining and Planning

Regardless of what kind of a writer you are, it’s smart to outline your story in this genre. I’d argue that it’s essential for managing the complexity that comes with sci-fi. An outline serves as a low-resolution draft, helping you discover the story and identify plot holes before you spend months writing thousands of words. It allows you to plan the promise, progress, and payoff of your narrative arcs.

The Three-Act Structure

Even if you’re not a fan of outlining, you might want to consider the three-act structure. This is pretty standard and serves as a reliable framework for any story. Here’s how it would go:

• Act 1 introduces the setting and the inciting incident that pulls the protagonist out of their comfort zone. 
• Act 2 explores the confrontation, where the character faces trials that escalate the stakes.
• Act 3 brings the resolution, where the protagonist makes a final, irreversible choice and the world settles into a new normal.

You can obviously build on this, adding more complex elements and what not, but the premise needs to be straightforward for you—the writer—to keep track of where your story is going.

Powerful Hooks and Opening Lines

A powerful hook is vital for establishing trust with readers. Your opening lines should raise immediate questions that make the reader desperate to turn the page. You might begin by revealing a piece of the ending, dropping the reader directly into the action, or showcasing a character’s unique perspective through a single, evocative word.

I’ve got a full guide on opening lines for you to take a look at: How to Write an Opening Line That’ll Hook Readers Instantly.

Generating Suspense through Questions

Suspense is the currency of our art. By opening “loops” or questions in the reader’s mind early on,you ensure they will stick around even during slower sections of the narrative. The key is to answer those questions eventually but to replace them with even deeper mysteries along the way.

Avoiding Deus Ex Machina

Deus ex machina—the introduction of an unearned, sudden solution to a problem—is a major failure mode in sci-fi. If you introduce a new piece of technology in the final act just to save your hero, the reader will feel cheated. Every solution must be properly foreshadowed and earned through the established rules of your world.

There’s a lot more to structure than these points, of course—though these are the most valid for the genre. 

I’d recommend checking out my guide on: How to Structure Your Novel: A Step-by-Step Guide.

And yes, I still have to write a blog post on plotting. So, stick around for that:)

Scientific and Technological Integration

As I’ve mentioned in the earlier section, the “science” in science fiction must be more than just window dressing.

Research-Based Plausibility

Even if you are writing soft sci-fi, research is your best friend. Grounding your ideas in real scientific principles adds credibility and can provide a spark of inspiration for new plot points. If you plan to write about terraforming, for instance, look into current theories on how we might realistically change a planet’s atmosphere.

Avoiding Excessive Technobabble

Avoid overloading your prose with excessive technobabble—confusing, undefined jargon used to sound “sci-fi.” Instead, use accessible language and keep the tech terms to a minimum. It is often more effective to explain a complex idea in simple terms than to bog the reader down in a PhD-level lecture.

Science as a Plot Driver

Science should behave like a character that pushes against your protagonists. It should influence the conflict, throw obstacles in the character’s path, and color their journey. The human struggle with—or exploitation by—technology is the essence of the genre.

Technology Consistent with Itself

Your technology must be true to itself. If you have established that your ships can’t travel faster than light, you cannot break that rule later without a significant, scientifically reasoned shift in the world’s status quo. Contradictions in technology will cause the reader to lose trust in you as a storyteller.

Borrowing Expertise from Professionals

You don’t have to be a scientist to write sci-fi; you just have to be willing to ask. Many professionals are happy to answer short, pointed questions about their field of expertise. Talking to a Navy veteran about submarine bearings or a doctor about microgravity can provide those immersion anchors that make your world feel authentic.

Scientific and Technological Integration

As I’ve mentioned in the earlier section, the “science” in science fiction must be more than just window dressing.

Research-Based Plausibility

Even if you are writing soft sci-fi, research is your best friend. Grounding your ideas in real scientific principles adds credibility and can provide a spark of inspiration for new plot points. If you plan to write about terraforming, for instance, look into current theories on how we might realistically change a planet’s atmosphere.

Avoiding Excessive Technobabble

Avoid overloading your prose with excessive technobabble—confusing, undefined jargon used to sound “sci-fi.” Instead, use accessible language and keep the tech terms to a minimum. It is often more effective to explain a complex idea in simple terms than to bog the reader down in a PhD-level lecture.

Science as a Plot Driver

Science should behave like a character that pushes against your protagonists. It should influence the conflict, throw obstacles in the character’s path, and color their journey. The human struggle with—or exploitation by—technology is the essence of the genre.

Technology Consistent with Itself

Your technology must be true to itself. If you have established that your ships can’t travel faster than light, you cannot break that rule later without a significant, scientifically reasoned shift in the world’s status quo. Contradictions in technology will cause the reader to lose trust in you as a storyteller.

Borrowing Expertise from Professionals

You don’t have to be a scientist to write sci-fi; you just have to be willing to ask. Many professionals are happy to answer short, pointed questions about their field of expertise. Talking to a Navy veteran about submarine bearings or a doctor about microgravity can provide those immersion anchors that make your world feel authentic.

Craft and Stylistic Tips

The style of your writing affects how close the reader feels to the narrator and the story.

Point of View (First vs. Third Person)

Choosing between first person and third person significantly impacts a story. Choose between POVs based on your comfort as well as how it would affect your story.

• First person offers an intimate, psychoanalytical distance between the narrator (the person telling the story after the fact) and the character (the person the story is happening to). 
• Third person provides a more distant, objective experience that can give the reader a broader appreciation of the world and multiple characters. 

Trusting Reader Intelligence

New writers often explain too much. Trust your readers—they are often smarter than you think and can intuit the rules of your world through action rather than exposition. 

Constraints as Creative Opportunities

Constraints, such as word count limits or the limitations of a specific POV, are actually opportunities for creativity. Having absolute freedom can be crippling. Being forced to solve a narrative problem within a set of rules often leads to your best ideas. Trust your personal demon when a wild gamble or a crazy idea deviates from your plan.

Using All Five Senses for Immersion

To make an extraordinary setting vivid, you must engage all five senses. Don’t just tell the reader what a planet looks like; tell them how the air smells, the sound of the strange winds, and the texture of the soil.

Precision and Subtlety in Writing

Greater precision in your prose—saying more with fewer words—makes for a tighter, more engaging story. Avoid repetition and trust that a single, well-placed detail (like a character’s nostrils flaring) is enough to convey an emotion without needing to state it explicitly.

Controlling Word Count and Length

While sci-fi is known for its sprawling epics, debut authors are often advised to keep their word counts between 90,000 and 125,000 words. Shorter books are often more precious and effective, as they don’t overstay their welcome and require more precise, dense prose.

Themes and Big Ideas

Science fiction provides a unique platform to tackle the most profound questions of the human experience.

Social and Political Commentary

The genre is inherently political, often paralleling futuristic worlds with current social issues. By looking at totalitarian regimes of the past, authors like George Orwell created chilling tales that warned of future dictatorial power. Your setting should be a lens through which readers can examine their own present reality.

Philosophical Conflicts

Sci-fi often explores deep philosophical conflicts, such as the nature of free will versus destiny or the tension between nihilism and optimism. These conflicts are best handled through drama, forcing characters to suffer for their beliefs and act them out in the world.

Humanity’s Relationship with Tech

A central theme of the genre is humanity’s relationship with technology. Show how characters both exploit and are exploited by their own inventions. The story should ask: “At what point in the technological revolution does humanity become something else?”

Moral Dilemmas and Consequences

Place your protagonist’s morality at the center of the story. They should face tough choices with no easy answers, forcing them to reveal their true character. In the end, the story should ideally show the irrepressible nature of human empathy and resilience, even in the most alien circumstances.

Preparation and Revision

Writing sci-fi is an iterative process that requires both deep study and meticulous editing.

Studying the Masters of Sci-Fi

My honest advice to anyone thinking about writing science is to study the masters. Read the classics—Frank Herbert, Isaac Asimov, Ursula K. Le Guin, Mary Shelley—to understand the conventions and how they have evolved over decades. Pay close attention to how they balance worldbuilding with narrative pace.

Deep Reading in the Niche

Beyond the classics, read deeply in your chosen subgenre. This familiarizes you with the specific tropes and features of that niche, allowing you to either play into them or subvert them in inventive ways.

Eliminating Repetition in Editing

Revision is where the story is truly polished. Use the editing phase to eliminate repetition and cut anything that doesn’t advance the plot, characterization, or worldbuilding. Be willing to delete entire sections that don’t work to make space for something better.

Verifying World Consistency

Finish your writing process by circling back to your foundations: verify your world’s consistency. Ensure that every rule of science or magic remains intact throughout the narrative and that no technological contradictions have crept into the later chapters.

FAQs

What makes a story science fiction vs. fantasy?

The difference is an argued versus unargued departure from reality. Sci-fi explains its deviations through technology and scientific logic, whereas fantasy relies on the inexplicable or the supernatural.

Do I need a science background to write sci-fi?

No. You only need the willingness to prepare and research the specific concepts central to your story.

What’s the difference between hard and soft sci-fi?

Hard sci-fi focuses on technical accuracy and physical sciences (physics, chemistry). Soft sci-fi focuses on social sciences (psychology, sociology) and human emotions.

How do I avoid info-dumping worldbuilding?

Release information organically through action, dialogue, and character experience. Let the reader discover the world through the eyes of an active character rather than a long prologue.

What is a novum in science fiction?

A “novum” is a novel insertion—a discovery or technological change—that transforms an otherwise normal situation and defines the science-fictional nature of the story.