How to Write Believable Sci-Fi Characters

Believe it or not, the rules for writing believable sci-fi characters are the same as writing any other kind of credible character in any other genre of fiction.

Ever written a character who was flat?



Or just otherwise unrealistic and unbelievable?

We all have. This is, arguably, one of the hardest tasks for any writer, no matter what genre he or she writes in. Creating memorable, realistic characters who jump off the page is freakin’ hard. Not all writers succeed at it. Most don’t.

So how is it done, then? How do you write believable sci-fi characters?

Believe it or not, the rules for writing believable sci-fi characters are the same as writing any other kind of credible character in any other genre of fiction. I, science fiction author Andrew Timothy Post, have once again scoured the Internet to bring you some of those rules, in the hope that they may help you write splendiferous science fiction. (And believe you me, writing believable sci-fi characters is a huge part of writing splendiferous sci-fi fiction. I can’t tell you how many times I’ve checked major sci-fi magazines’ submission guidelines and seen the phrase “We prefer character-driven sci-fi.”)

So, without further ado, here are


#1. Make your characters consistent.

In his gut-bustingly funny essay Fenimore Cooper’s Literary Offenses, Mark Twain lays out a scathingly comprehensive list of literary gaffes that the writer James Fenimore Cooper routinely makes in his famous Leatherstocking Tales, of which The Last of the Mohicans is a part. One of the ways Cooper routinely makes his characters unbelievable is making them speak inconsistently. A Cooper character will start out talking like an uneducated hayseed at the beginning of a sentence, and by the end of it they’ll sound like an educated Boston snob. Don’t do this in your own fiction. Make sure that the dialect or accent or verbal tic that your characters use remains consistent throughout their speech and throughout the story.

…as an example of what not to do.

This also applies to your characters’ behavior. If your character has spent the entire book as a shrinking violet, don’t suddenly make her a courageous hero (unless it’s important to the story, and unless there’s some inciting event that makes her sudden transition make sense). In short, don’t jerk your readers around. They’re trying to get an idea of your characters’, well…character. Keep it consistent so your readers catch on as quickly as possible. Your characters should be so consistent that your readers should be able to tell exactly what a given character would do in any situation without you having to write it. That’s the trick to writing believable sci-fi characters.

#2. Give your characters wants and needs.

Kurt Vonnegut famously had eight rules for writing. The third rule is this:

Every character should want something, even if it is only a glass of water.

…or a decent headshot.

A great deal of the flatness in today’s literary characters (even those found in some popular novels!) is rooted in the fact that they don’t seem to want anything. They’re just…there. The most boring and unbelievable villains are those who have no obvious goal. They’re just doing it “for the evulz.” Occasionally a chaotic evil villain can be an interesting character. Emphasis on “occasionally.” Usually it’s only experienced, established writers who can get away with writing a villain with no motivation. If you’re an experienced and established writer, and you’re reading this, bravo. You’re on Easy Street. If you’re not established and experienced, then you better make your villain believable and give ’em some kind of need, some goal they’re striving for. Bonus points if it’s the exact opposite goal that the hero is striving for. That makes for interesting fiction.

Even the minor characters in your stories need to have something they want. A hope, a dream, a goal, an ambition, a desire, a need. Doesn’t have to be anything huge. Like Vonnegut said, it could be as simple as a glass of water.

Pictured: a minor character who just wants to listen to the radio at a reasonable volume.

Imagine how funny a scene would be where your protagonist and his or her significant other are arguing, and they work in a pharmacy, behind the counter, and there’s this poor old customer at the till who’s trying to get them to fill his prescription, and your protagonist and his or her significant other ignore him throughout the whole scene, because they’re each focused on getting what they want out of the conversation and too wrapped up in the argument to do their jobs properly. That guy in the background, instead of just standing there blinking like a one-dimensional character, keeps asking them to get him his prescription for Flonase, but they ignore him.

This gives even the background character dimension. All he wants is his allergy medicine. And he can’t get it, because the two main characters are having a fight behind the counter. That makes for something called drama. It makes the reader interested. Will that poor guy ever get his Flonase? It makes people want to keep reading and find out. Believable sci-fi characters with pressing wants and needs are what get your readers hooked on your story.

#3. Make your characters distinct.

Let’s say the hero in your story is tall, strong, muscular, skilled with weapons, and was raised by a one-parent household, or was an orphan. Great, that’s interesting. Will he still be as interesting if five other characters in your story are also tall, strong, muscular, martially inclined, and had rough childhoods? No. Suddenly there’s nothing special about your character anymore. Nothing to remember. No spark of interest.

I hate to use Star Wars as an example (because Star Wars isn’t technically sci-fi; it’s fantasy). But there are some memorable and believable characters in there (at least in the original trilogy). Look at the three main characters of Episode IV: A New Hope.

Sorry, Chewie, you’re just a sidekick.

Luke Skywalker is a young farm boy from a backwater planet. He grew up fast, on an unforgiving frontier. He’s brash, idealistic, adventurous, and thirsts to prove himself. He wants nothing more than to get off his backwater planet and have howling adventures among the stars.

Leia Organa is a determined and politically active princess from an aristocratic family on a lush and temperate planet nearer the Galactic Center. She never lacked for anything when she was growing up, but she’s still willing to step up and fight for what she believes in. She wants nothing more than to get the information in her possession to her allies and use it to defeat the Galactic Empire.

Han Solo is slightly older than Luke and Leia. He grew up on the mean streets of a heavily urbanized and crime-ridden planet. He fell in with the wrong crowd at a young age. He was in the military, but lost his faith in its mission when he witnessed the Empire’s cruelty. He is brash, but unlike Luke, his risks are calculated ones. He is also cynical, and amused by Luke’s youthful idealism and Leia’s political activism, seeing both of them as small-minded and trivial. Han only wants to enrich himself: to pay off his debt to Jabba the Hutt and then continue his freewheeling lifestyle across the stars.

See what I mean? These characters, at least at the start of the story, couldn’t be more different. They each come from vastly different backgrounds. They have different outlooks on life (which are believable outlooks, molded by their upbringing and experiences). And they each have different desires, some of which are at odds with the others’ desires. Some of the most delightful moments of drama and humor in A New Hope come from these three characters learning to cooperate despite their different outlooks and desires.

People aren’t grains of rice. They’re snowflakes. Everybody’s different. Everyone has a uniquely different background, a uniquely different belief system, and a set of quirks and flaws.

And speaking of flaws…

#4. For Pete’s sake, make your characters flawed.

Once upon a time, there was a character. Her name was Mary Sue. She was perfect in every way. She had no flaws, never made any mistakes, and everything she tried worked out like she’d planned it to. She went through her entire life never experiencing loss, hardship, inconvenience, difficulty, stress, or drama. She died as she was born: perfect in every way. 


Doesn’t that sound boring as hell?

Of course it does.

Now try this:

Mary Sue had a problem with authority. Her father was a very controlling man, and tried to get her to act and dress and speak exactly the way he thought she should. So Mary Sue grew up with the idea that authority figures were all bad people with unfair ideas, and when she got to high school, she resisted any attempt by teachers or the principal to control her. She sat with her legs flung over the desk, drew graffiti on the bathroom walls, started food fights in the cafeteria, doodled in class, smoked during recess. The harder the teachers and principal tried to control her, the harder she resisted. She was kicked out of five schools before her father lost all patience. He sent her to Summerlin Military Boarding School, where she and other “problem children” were sent when their parents and teachers were at their wits’ end. And in charge of that school was Colonel Martin DeForest, Vietnam veteran, who’d straightened out more “problem children” in his lifetime than any other head of any other similar institution. 

Mary Sue’s first day of school was rougher than expected…

Is that better?

Of course it is.

See? We’ve got a character with a flaw, now: a lack of respect for authority. Even though Mary Sue has a good reason for having this flaw, it’s getting her into trouble. Up until this point, she’s found no compelling reason to change her behavior. Suddenly, though, she’s at a military boarding school, and the headmaster is a whole lot tougher than any other authority figure she’s ever met. Suddenly, we have the makings for drama. For conflict. For suspense. I bet you’re probably curious what happened on Mary Sue’s first day of school—how she acted out, and how Colonel DeForest came down on her, and what happened after that. Maybe you’re even forming a hypothesis about the ending of the book: maybe Mary Sue realizes that her disrespect for authority isn’t universally applicable and becomes a more tractable person, and maybe even DeForest realizes that his usual methods don’t work with every problem child and softens his approach.

And that’s the point, actually. Your characters should change. They should not be the same person at the end of the story that they were when they started. Libbie Hawker’s excellent book Take Off Your Pants! goes into this in great detail. Your character should start with a flaw. They should have some sort of debilitating character tic that gets them into trouble and creates conflict and drama. They should fight and kick against fate, make a few mistakes, learn from said mistakes, and then grow and mature into a better person. This is immensely rewarding to the reader and keeps them hooked on the story. And it’s realistic, too. People don’t stay the same person their entire lives. (Some do, but most don’t.) They change. They learn. They alter their behavior. Believable sci-fi characters can sometimes even undergo a complete personality change.

Take Star Wars for instance. By the end of Episode IV, Luke is no longer the naive and idealistic farm boy he was when the story started; he’s a fully fledged member of Rogue Squadron, a hero to the Rebel Alliance, and a budding Jedi Knight. How far he’s come. How much of his original naivete he’s lost. Han Solo is no longer the cynical rogue he was at the beginning, either: he’s a true friend, a selfless warrior, and a key player in the rebellion as well. Leia is no longer the stressed-out, desperate person she was at the beginning of the film; she’s achieved her goal of bringing the information to her allies and destroying the Death Star. She’s happy and contented.

You know how exhilarated you were at the end of Star Wars: Episode IV when you watched it for the first time? This is why. The characters changed. In a satisfying way. They overcame hardship. They struggled. They fought. They triumphed. They were real. They were believable. And you fell in love with them. There’s a reason the Star Wars franchise (at least the original trilogy) is one of the most beloved film franchises of all time, all around the world.

Character counts.

Now get off the Internet and start writing some believable sci-fi characters.


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Author: Andrew T. Post

Andrew T. Post is a science fiction writer, journalist, traveler, thinker, and blogger based in the Central Valley of California.

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