Sci-Fi Worldbuilding: How to Construct an Unforgettable Universe

Abi Wurdeman
April 20, 2023

Sci-fi worldbuilding comes with a lot of contradictory rules.

Let your imagination run wild but ground it in research. Transport your readers to a world that’s nothing like anything they’ve ever known but make it feel real. Nail the science but remember it’s not really about science.

No one would blame you for feeling a little lost. Sci-fi worldbuilding is going to draw you deep into the weeds, but don’t worry. I’m going to give you the tools you need to bushwhack your way out.

You’re about to learn:

  • How detailed to get with your worldbuilding
  • How much research you need to do to build your science fiction world
  • What it takes to design an imagined setting that feels real
  • Why sci-fi worldbuilding is different from creating worlds in other genres
  • How to keep your hot mess of ideas organized

I can’t promise your worldbuilding experience won’t get a little chaotic. But I can help you stay sane and clear headed through the chaos. Ready?

Let’s do this.

Step 1: Set Some Parameters

Small, handmade planets dangle against a black background.

Sci-fi worldbuilding can get pretty overwhelming, especially when there’s a fantasy element. When the only limit is your imagination, how do you even know where to begin? Or where to end, for that matter? 

It may reassure you to know that even your imagination needs to operate within a few guidelines.

For one thing, there’s the golden rule of worldbuilding: 

Your world serves your story. 

It's not the other way around. If it doesn’t support your plot and it’s not necessary to give the reader a strong sense of place, you don’t need it.

Now, you may not know exactly what your sci-fi story needs from your setting right now. You might not even know what your story is. It’s perfectly fine to build your story and your world simultaneously. 

Just note that the longer you go without a story, the greater your risk of outlining every battle of an intergalactic war only to realize your reader just needs to know who won in the end.

Second, let your favorite authors help you set some guidelines.

Read science fiction books as you build your world (and as you draft and revise your novel). Notice how other authors describe their world. What information do they give you and what do they leave up to your imagination? Why do you think they make those choices?

More importantly, does their approach work?

Of course, some authors divulge more details than others. That’s why you want to do this exercise with sci-fi novels that fit in the same category as your soon-to-be book

What do I mean by “category?” So glad you asked.

Step 2: Categorize Your Sci-Fi Novel

Bookshelves full of sci-fi books in a bookshop.

To set clearer sci-fi worldbuilding parameters for your book, you have to know where your book belongs on the science spectrum.

In other words, are you writing hard science fiction, soft science fiction, or science fantasy?

Hard Science Fiction

Hard science fiction novels take the science part of sci-fi very seriously. Readers of hard sci-fi expect to hear a lot about the science of your world. They want specifics and accuracy. Physical sciences like astronomy and biology tend to play a starring role in hard science fiction.

If you're writing in this category, your sci-fi worldbuilding will involve things like:

  • Researching scientific laws
  • Reasoning through the plausibility of the way those laws are applied in your story
  • Imagining what it would look like to take current scientific advancements to the next level
  • Imagining how those advancements would reshape society
  • Softly sobbing in the library when a textbook pokes a hole in your story

Soft Science Fiction

Soft science fiction doesn't concern itself quite as much with explaining the physical probabilities of your book’s sci-fi elements. There’s more focus on the human experience of living with that science. Societal, psychological, and emotional consequences take center stage.

“Soft science fiction” can also refer to sci-fi books that entertain a thought experiment concerning a science like psychology, sociology, or anthropology.

If you’re writing in this category, your sci-fi worldbuilding will involve things like:

  • Dreaming up a scientific advancement that would transform society or present an ethical dilemma
  • Outlining transformations in big-picture areas such as laws, taboos, power structures, and free will
  • Exploring transformations in more intimate situations like relationships, identity, and family structure
  • Possibly doing some research to make sure the science is at least plausible and vaguely explainable

Science Fantasy

Science fantasy is a blend of science and fantasy. Go figure.

In science fantasy, there are both scientific elements—such as technology—and fantasy elements—such as creatures that are not known to actually exist. This subgenre borrows tropes from both sci-fi and fantasy. It's super fun.

As you might guess, science fantasy is another category that does not require a ton of scientific explanation. You could go deep on science if you wanted to, but most science fantasy authors choose not to juxtapose the explainable and the unexplainable.

Star Wars is a classic example of science fantasy. There are clones (a scientific concept) and there are high-foreheaded, humanoid teddy bears (pure fantasy, to the best of my knowledge). 

If you’re writing in this category, your sci-fi worldbuilding will involve things like:

  • Dreaming up interesting scientific advancements
  • Doing enough research to reference those advancements in a way that sounds like you know what you’re talking about
  • Considering how the science of your story would influence society, government, and day-to-day life
  • Creating a fantasy world (Psst. Here’s a fantasy worldbuilding guide to help you out.)

Now, there's a decent chance whatever book you're imagining doesn't fit into a single category. Even hard and soft sci-fi can overlap. Google reading lists in either category and you will probably find Octavia Butler’s name everywhere. Her work can go deep on science, but she was always exploring human issues. 

So don't obsess over where your book fits exactly. Just use these categories to start getting a sense of how to focus your sci-fi worldbuilding efforts. Then narrow it down further by finding what category your world fits into.

Step 3: Categorize Your World

Sci-fi worlds tend to fit in one of the following four categories.

Real World 

This is the world we know and live in, past or present, but with science fiction elements at play. If you're writing real-world sci-fi, you don't have to worry so much about constructing an entirely new reality.

Instead, you'll zero in on the specific technology or a scientific phenomenon at the heart of your story. Often, the science element of real-world sci-fi is only known to a few characters. Society continues on as it always has while the central characters time travel or bust ghosts. 

Alternate Reality

Alternate reality presents alternate versions of our past or present world. This can include reimagined history, like The Man in the High Castle. It can also include parallel universes or other dimensions in the present day, as is the case with Dark Matter.

If you're setting your sci-fi novel in an alternate reality, the amount of worldbuilding you have to do depends on the nature of your story. You might do some historical research and then add sci-fi elements to the world of the past. Or you might imagine an entirely new reality altogether.

Speculative Future

A speculative future sci-fi novel imagines how our current reality could change under a specific set of circumstances. The Handmaid’s Tale is set in a speculative future world, one in which a fundamentalist regime has gained totalitarian control over the United States.

For this type of world, your sci-fi worldbuilding will be guided by the larger question posed by your novel. Let’s say you want to tell a story that answers the question “What if there was an app that allowed us to read each other’s thoughts?”

Start imagining the answer and how that answer would influence aspects of your setting. 


This one is fairly self-explanatory. A fantasy world is one that does not exist and never has existed. This includes made-up planets and alien spaceships.

If you’re building a science fantasy world, you’ve got a lot of worldbuilding to do. And a lot of it is going to come from your own imagination. You'll need to dream up everything from the terrain to the political history. 

The upside? You probably can worry a little bit less about scientific accuracy. To a degree, at least; if you have humans breathing on another planet, that planet needs an atmosphere. Or magic.

Now that you have a better grip on what your world looks like and how much you need to know about it, let's dig into the two areas that you'll be fleshing out: the scientific and the fantastical.

Step 4: Master the Science of Your World

Hacker code

The two greatest challenges when it comes to the science part of sci-fi worldbuilding are:

  1. Researching and comprehending science so you can write about it like you know what you're talking about
  2. Determining when you know enough to make the world feel authentic to your reader

Here are a few tips for overcoming these issues.

Start with a question. Science fiction is a question-driven genre. Whatever story you're telling, it was likely inspired by a “what if” question. 

What if scientists cloned dinosaurs and started a dinosaur theme park? What if humanity advanced beyond bigotry and a team of humans served as intergalactic diplomats to a universe still rife with prejudice? 

Try to nail down your question if you haven’t already.

Make a list of all the scientific concepts you need to understand in order to sell this world to your audience. For example, if you’re writing the dinosaur clone story (even though it’s been done), you’ll need to know about cloning and dinosaurs.

Include things you don't know and plan to double-check the things you believe you already know. Might as well be thorough.

Think through your characters’ everyday life. What’s the breakfast situation like on your spacecraft? Is the government really watching them 24/7… like, everywhere? 

By walking through daily life in your world, you can catch the little science-centered questions that are bound to come up as you draft your novel. Make them make sense now so they don’t unravel your story later.

Use multiple resources for your research. Take that list of questions to Google, your library, any experts you can find, and academic journals. It can be especially valuable to reach out to experts, as they can talk through an idea and help explore alternatives if your original idea isn’t plausible.

As for the things you can’t research...

Step 5: Master the Fantasy of Your World 

The challenge of building a fantasy world is that it’s easy to assume you’re working with zero limitations. That’s not exactly true. There are very few restrictions when it comes to inventing your own reality, but they do exist.

And working with those restrictions actually makes your world more captivating. You’ll see why as I lay out some key tips for designing the fantasy elements of your world. 

First, set some worldbuilding goals up front. These goals will probably evolve. Story and world have a tendency to inspire one another. But I recommend doing your best to identify a few must-build aspects of your world from the get-go. 

Does your reader need to know the name of every member of the alien fraternity that calls the shots on this planet? Maybe yes, maybe no. Do they need to know the names of the fraternity members’ kids? Probably not. 

Draw a line there and don’t let yourself get nailed with Worldbuilder’s Disease.

Treat the laws of magic as seriously as the laws of science. If you want to sell something as real, it has to make sense. Who holds the magic? Why them? What are the limitations of magic? Define them and respect them as you build your world and plot your novel.

Consider your tone. The fantasy elements of your sci-fi novel can do a lot of the heavy lifting when it comes to establishing a tone and maintaining a vibe. Is this a wonder-filled adventure on a forest planet? Or a seemingly hopeless mission in a desolate dimension? 

Now that we’ve laid out some ground rules for sci-fi worldbuilding, let’s dig into the specifics.

What exactly do you need to create to make this world real for your readers?

Step 6: Characters

Chewacca waving.

Character development is a subject for another article (several other articles, in fact).

But sci-fi worldbuilding still requires you to determine who will populate the universe of your novel. Here are a few things to consider.

If you’re constructing an entirely new species, what are their physical qualities? How do they differ from humans? (If you pull inspiration from exiting human societies, be careful to avoid creating characters that dehumanize or stereotype real cultures.)

On the other hand, if you’re imagining a future or alternate reality containing humans, how are these humans different because of their unique circumstances? Do they have any unique skills, routines, or adaptations that are a direct result of your sci-fi world?

Are any of your characters also technology? In that case, to what degree do they resemble humans? 

Who holds the power in this world? Who seeks power? Is anyone oppressed or an outsider? 

When you eventually write this thing, will you tell it from the point of view of a specific character? If so, start thinking about how this character would perceive the world. What details are important to them?

Finally, how do your characters speak? Do they work with an adapted language like Newspeak in 1984? Will you need to create a conlang (constructed language) for an alien race?

Got your answers? Good. Because it’s time to talk about your physical and cultural setting.

Step 7: Ships, Planets, and Everything in Between

The silhouette of a person staring up at a multi-colored sky full of stars.

Sci-fi worldbuilding might mean designing a spacecraft and the culture of the flight crew. It could mean reimagining all of Asia. Or it could mean constructing an entire galaxy. 

However big or small your sci-fi world is, you need to consider both its physical and cultural attributes. This general worldbuilding guide goes deeper into these categories, but for now, here’s a quick snapshot of those attributes.

The physical world of your story refers to everything that exists without human (or human-adjacent) intervention. This includes:

  • Landscape, borders, and terrain
  • Flora and fauna
  • Climate
  • Natural resources
  • Cosmology
  • Laws of science
  • Laws of magic

The cultural world of your story refers to everything that exists because the beings in your sci-fi world made it so. This includes:

  • Language
  • Religion
  • History
  • Tradition
  • Social, economic, and political structures
  • Food, fashion, and entertainment
  • Industry
  • Military
  • Art
  • Architecture
  • Education
  • Technology

These are just starter lists. As you begin imagining these aspects of your world, you’ll probably find yourself adding additional elements. 

Also note that you don’t have to think about all of these things. Your book may not require a map or a conlang. Build what makes sense—what supports the story, contributes to conflict, and makes the world feel real.

One more sci-fi worldbuilding tip: build in threats. Natural predators, dangerous terrain, invisible surveillance cameras… any sinister additions that serve your story.

Step 8: Technology

Finally, let’s talk about the tech that makes your sci-fi world go ‘round. Here are some tips for dreaming it up and designing a world around it.

Draw inspiration from reality. If you’re stuck, think about the things you use every day and imagine what it would look like to push them further. Or think of a problem you wish technology already had a solution for. 

Create limitations, too. Just like magic, made-up technology is most interesting when it can’t do everything. What are the limits of tech in your universe? 

Keep it consistent. If the robot can’t feel emotion, don’t let it come to the protagonist’s aid just out of principle. Whatever rules you establish for your technology, stick to them unless the change tracks with the story. 

Be mindful of time. How long would it take your characters to get across the galaxy in that shuttle or across town on that flying scooter? Would it still take half a day to cook a Thanksgiving turkey in the year 2506? Will a business meeting be a long enough distraction for your protagonist to pull off a heist in a world where everyone communicates telepathically? 

It’s a lot to think about, I know. That’s why I’m going to offer one final suggestion.

Create a Sci-Fi Worldbuilding Bible

Your sci-fi worldbuilding bible is the place where you keep all the details of your world. Maps, history, science research… all of it. When you have this information organized and always at hand, you free up a lot of brain space for writing a stellar story.

My favorite way to keep track of story information is using the Story Notes feature in Dabble. Folders and notes are completely customizable so you can organize your sci-fi world however you’d like. You can also upload images and search for photos right there within your notes.

A screenshot demonstrating an image search in a sci-fi worldbuilding bible in Dabble.
It seriously could not be easier.

Best of all, this information is just one click away as you draft your sci-fi novel.

If you don’t already use Dabble, you can give it a whirl right now for zero dollars and zero cents. A fourteen-day free trial gives you access to all the Premium Features, no credit card required. Click here to get started.

Abi Wurdeman

Abi Wurdeman is the author of Cross-Section of a Human Heart: A Memoir of Early Adulthood, as well as the novella, Holiday Gifts for Insufferable People. She also writes for film and television with her brother and writing partner, Phil Wurdeman. On occasion, Abi pretends to be a poet. One of her poems is (legally) stamped into a sidewalk in Santa Clarita, California. When she’s not writing, Abi is most likely hiking, reading, or texting her mother pictures of her houseplants to ask why they look like that.