Magic or Technology? A Writer's Guide to Choosing Between Fantasy and Sci-Fi

If you’re anything like me, you probably find the idea of writing about our very real, modern, and clearly existing world deeply uninspiring.

Writing is the time we dedicate to escaping the world we know into one we conjure on the page, so writing about that same familiar world sort of defeats the purpose.

And it makes sense—if our minds can create places and people we’ve never seen before, why limit ourselves to the safety of the known?

When weaving a different reality as the stage for the events of our story, we tend to focus on things that aren’t possible in our world but can exist on the page. Magic, inventions that stretch the bounds of possibility, or laws of physics that work differently than the ones we know here on earth.

The possibilities are endless, but the fictional landscapes we build, however diverse, usually fall under one of two umbrellas: fantasy or science fiction.

The line between the two, however, isn’t as clearly defined as you might think. If flying ships sound like futuristic technology, just look at the Death Gate Cycle and Haplo’s magic-powered dragon ship. And if fantasy feels permanently stuck in the ancient past, there are plenty of fantasy stories set in modern times, or hinting at eras after our own world has ceased to exist.

Still, while the genres overlap, there are meaningful differences between them, and more importantly, reader expectations you’ll want to meet. So if you’re debating whether your story should rely on advanced technology or mystical magic, here are a few things to consider.

The Inner Mechanics of Magic

Flying ships can be made of wood and powered by some magical orb, or crafted from metal and run on sophisticated technology. The key difference isn’t just what powers them, but how well you understand that power.

In science fiction, writers are generally expected to explain how things work, even if only at a high level.

It doesn’t have to be hard sci-fi that reads more like an instruction manual than a story, but it does need internal logic. Spaceships, speed, and means of travel should feel grounded in cause and effect.

The technology can be wildly advanced or even implausible, but it must be internally consistent—and readers tend to expect that consistency.

Fantasy, on the other hand, is more forgiving when it comes to explanation, especially around magic. This doesn’t mean magic should be all-powerful or undefined—it can have sources like life force, crystals, powerful deities, or shamanistic toads—but fantasy readers rarely want a deep dive into how a spell technically works (though I included some of those here). In fact, too much explanation can drain the magic out of it (pun intended).

If complex systems and mechanical breakdowns aren’t where you shine, a fantasy landscape may simply be better suited to the story you want to tell.

Stone and Metal

While both genres create worlds far removed from the Earth we know, their physical environments feel very different.

Sci-fi worlds tend to be futuristic, filled with technology, devices, and machinery. Even dusty, post-apocalyptic deserts usually carry traces of advanced civilization—mechanized transport, robots, artificial intelligence—hinting at what once was, or still is.

Fantasy worlds, meanwhile, often lean in the opposite direction. On dragon-infested shores, metal is more likely to be found in armor or castle gates than in circuitry. Devices may exist, but they're rarely powered by electricity or tangled in wires.

Structures are typically built from stone and wood, with metal predominantly reserved for weapons (and not the kind that shoot lasers).

Aesthetics matter in writing. If you love your sunshine glinting off chrome hulls and glowing panels, sci-fi may be your home.

Aliens and Dragons

Another way in which the fantasy and the sci-fi worlds are similar is in the potential abundance of non-human races and creatures. However, each genre approaches them in a very different way.

In science fiction, alien species are often humanoid civilizations with advanced technology. Just like faster-than-light travel, alien biology usually needs to make some kind of sense. Readers tend to expect plausibility, or at least a convincing attempt at it. A fire-breathing organic creature might be a harder sell unless you can back it up with biology that sounds believable.

Fantasy offers more flexibility. Many things that fall apart under scientific scrutiny can be simply explained by magic. This is not to say fantasy creatures don’t need internal consistency, but readers are far more accustomed to encountering beings pulled from folklore and fairy tales without worrying about their anatomy.

After all, has any fantasy writer ever explained whether fairy dust is a dried form of sweat? And more importantly, would you want that answered?

Conclusion

Choosing the genre that best fits your story ultimately comes down to preference. What makes your eyes widen, and your imagination spark? An intergalactic spaceship, or a sword-wielding hero riding a dragon? Do you get more excited watching The Lord of the Rings or Star Wars?

Genre expectations can guide you, but the answer doesn’t have to be either/or.

You could write a sci-fi story where a mysterious source of magic is discovered, or a fantasy world suddenly visited by a spaceship-flying civilization.

An urban fantasy about an ordinary person stumbling upon a portal to another world is another way to blend genres.

And if deciding between sci-fi and fantasy still feels overwhelming, the considerations above can help you make a choice that serves your story.

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