A shiny chrome airship hovers near a shiny chrome futuristic city, surrounded by a forested landscape

Image by Liu zishan on Shutterstock

When we add new places, cultures, or creatures to a world, we often view them as independent of everything that’s already there. But worlds are a system. Each element should work with the others to create something that’s more than the sum of its parts. Without this, a world will never stand out.

At Mythcreants, we use the term “theme” to describe the concepts that unify a world.* I started using this term in a 2014 podcast episode and wrote the original version of this article in 2016 (PDF). At the time, it was a relatively niche topic.

Over the years, theming has grown into a foundational principle. It’s related to many other aspects of the audience experience, such as tone and plot. Plus, of all the worldbuilding problems we find in the manuscripts we edit, theming issues are among the most common.

Unfortunately, my first version of this article didn’t do the topic justice. Using a theme means leaving out cool stuff you might want to include, so worldbuilders need a robust explanation for why they should make that sacrifice. This time, I want to give everyone a closer look at what a world theme is and why it’s important.

What’s a Theme?

Gold and teal plants of unusual shapes surrounding a gold path
Image by Tithi Luadthong on Shutterstock

Since most speculative fiction genres are largely determined by their setting, a world’s theme is closely related to its speculative genre. Once your audience knows your genre, they will use genre conventions to fill in many aspects of the world that you haven’t specified.

However, genres are seen as broad, predetermined categories, while every theme is unique. A theme encompasses many small or subtle components that don’t impact the story’s genre, but still work with genre elements to create a unified impression on the audience. Elements associated with different genres can also be mixed and matched into one theme, though doing so is more difficult than sticking to one genre.

Generally, a theme encompasses worldbuilding choices related to:

  • Metaphysics. This is how reality works. You might have a divine presence that dreams reality or a universe with only two dimensions. You might stick to the hard science of the real world or depict a magical world that’s similar, but distinct from, Earth. The metaphysics of a world are crucial for setting expectations about what is and isn’t possible. This is why if you mix world elements that suggest different metaphysical rules, you can end up with believability issues.
  • Aesthetics. This is all the stuff in your world and the imagery those things create. Your world might be full of waterfalls and misty ruins, fiber optics and silicon constructs, or clockwork and steam engines. When building a world, this is probably what you’ll think of first, and aesthetics are easy for audiences to remember. Just keep in mind that all of it comes with associations, implying things about your world’s genre, metaphysics, and atmosphere. For instance, clockwork suggests a specific technology level, and it’s associated with the steampunk genre.
  • Atmosphere. This is the feeling the audience takes away from the world, especially once narrative choices are made. Do your mages arrange happy endings with rainbow magic or sacrifice people to appease uncaring gods? The level of realism in your world is especially critical, as it acts like metaphysics for the narrative. Can characters walk off severe injuries, or will they collapse before dying from infection several days later?

In turn, these choices impact a story’s tone from moment to moment. However, when we refer to theme, we mean the permanent aspects of the setting that work together, separate from the fluctuating choices of each story.

For instance, any of these could be the start of a theme:

  • In a broken future of crumbling infrastructure and polluted air, humanity has retreated into a glamorous virtual reality where anything is possible.
  • Castles wander on floating islands, sending dragon patrols to pillage the lands below and battle the great worms that emerge from deep chasms.
  • Under every bed, the pin people have built their tiny villages out of jewelry boxes and bottle caps.

To maintain the theme, all of the metaphysics, aesthetics, and atmosphere have to work together. Each one affects the other. If you include both circuit boards and magic wands, that suggests two different metaphysics. If you have both doomsday cults and flower fairies, that suggests different atmospheres.

This doesn’t mean you can’t have contrasting things in your world, but making contrasting elements work together takes more investment. Even with that investment, a theme can only handle so much contrast before it falls apart. Once that happens, you’ll have a collection of random stuff that doesn’t add up to anything.

Strongly Themed: Discworld

Discworld is a strong setting capable of holding Terry Prachett’s loose anthology of books together.

  • Metaphysics: Discworld is highly magical. There are magical species, several types of spellcasters, and an enormous pantheon of gods and god-like figures. Gods are powered by belief; they can become more or less powerful when they gain or lose followers. Common story narratives can also affect the world’s reality; the big library of the setting is a particularly potent source of reality-altering magic.
  • Aesthetics: Discworld uses all the trappings of fantasy, but without the glamorous edge that most fantasy stories give them. Each fantasy element is also given a unique twist that makes the world’s aesthetics more playful. For one thing, the world is a disc on top of elephants, on top of a sea turtle. The setting also includes some renaissance-era technology, such as signal towers and the printing press. When more advanced technology appears, it usually operates by magical means.
  • Atmosphere: Discworld is highly absurdist, and Pratchett uses this to make jokes that subvert fantasy tropes. While serious topics make a regular appearance in Discworld commentary, they are usually addressed in a playful manner.

Every aspect of Discworld is designed to let Terry Pratchett make lots of fantasy-related commentary while simultaneously offering a truly unique fantasy setting. The atmosphere of absurdism unites the playful aesthetics with the light and irreverent stories that unfold in the world.

Poorly Themed: The Marvel Cinematic Universe

The Marvel Cinematic Universe (MCU) is derived from many different comic books by different writers and artists. Each time a comic is brought to the big screen, Marvel is primarily concerned with how it portrays that individual story. To bring in existing fans, it needs to copy the iconic aspects of the comic.

Even though each story must adhere to its own rules, Marvel wants to make crossover stories, because they’re so popular. This has led to the MCU: a larger world where all the comic stories exist simultaneously. The end result is that it’s impossible to meet Marvel’s business needs while also maintaining a strong theme.

Let’s see what that looks like.

  • Metaphysics: The MCU includes incredibly advanced technology, magic, and gods that bestow divine power. People can get powers from natural genetic mutations, radiation, lab experiments, or high-tech suits. There are also stones that can completely reshape reality in the universe. Alternate universes and timelines frequently feature in the MCU.
  • Aesthetics: The MCU features aliens, magical monsters, spellbooks, spaceships, talking animals, artificial intelligence, magical glowing flowers, gods from different cultures, evil dead spirits, portals between dimensions, eye lasers, old ruins, and lots of superheroes in costume.
  • Atmosphere: Most of the MCU is low on realism and contains a fair amount of irreverent camp. With no metaphysical or aesthetic consistency, this strains believability less. However, some of the individual works in the MCU are significantly grittier.

The MCU has everything and the kitchen sink, but this is because of the constraints Marvel is working under. It’s not what Marvel would have chosen without those constraints. Marvel isn’t trying to make a name for itself for the first time; it’s already popular and is trying to make everyone happy.

The Benefits of a Theme

Brightly colored flying cars of various shapes and sizes drive through a smoggy city
Image by Tithi Luadthong on Shutterstock

While some themes are looser and can include more variety than others, a theme will always require banishing some elements from the setting. Let’s look at why having a theme is important enough to give things up.

It Creates a Stronger Impression

It’s difficult to describe the MCU accurately in a few words, because there’s no shorthand for all the things in there other than “comics,” which is vague. On the other hand, if you say Discworld is “a subversive and absurdist fantasy setting,” that pretty much sums it up. Since people’s memories are limited, this ability to succinctly describe a setting also reflects people’s ability to remember what’s special about it.

Let me put it another way. Imagine a room packed wall to wall with a diverse collection of items, such as teapots, computers, puzzles, books, rugs, clocks, paintings, notebooks, lamps, and globes. Now imagine the next room is packed wall to wall with clocks. All clocks of various shapes and sizes, everywhere. Which room feels more remarkable? Which room are you most likely to tell someone else about? Which one will you remember longer?

If you want your audience to rave to their friends about your world, a strong impression matters.

It Lowers Cognitive Load

Audiences can only handle so much complexity. When a work is too complicated, they’re more likely to mix up and forget critical details. It can get to the point where there’s so much exposition the story is boring, and yet the audience still can’t keep track of everything. While complexity can come from lots of places, worlds are frequently the biggest contributor.

You can fix this by cutting stuff from your world, but most of us don’t want to do that. A less painful alternative is to consolidate everything. That means making existing elements feel more related, so they require less mental space. Imagine you’re in that room full of teapots, computers, puzzles, books, rugs, clocks, paintings, notebooks, lamps, and globes. You wave a magic wand and turn all of them into clocks.

When everything in the world fits intuitively together, the audience has a much easier time remembering it all. That’s because one element of the world provides a natural reminder for the other elements. If the audience doesn’t have to work so hard to keep everything straight, you don’t have to cut as much.

It Bolsters Believability

Audiences accept many fantastical elements because of their metaphysical backing. If you have a pegasus in a fantasy setting, the audience won’t question how an animal as heavy as a horse could possibly fly with wings of that size. They won’t ask how the pegasus evolved and whether it’s a mammal or a bird. They’ll just assume the pegasus is magical, because the fantasy aesthetics imply magic exists.

If you plop that pegasus in a setting that uses scientific metaphysics rather than magical ones, the audience will use a scientific lens for it instead. They’ll start asking all of those inconvenient questions about how this pegasus can exist.

These problems are especially likely when you mix genres, because genre expectations improve believability. After a while, people get more used to common conventions and stop asking as many questions about them. But in most cases, you’ll want to do more than copy genre conventions. When you deviate, a strong theme can provide an alternate set of expectations that makes readers feel like new elements are a natural fit for the world.

That’s worth it, because when readers are jarred by something that doesn’t fit expectations, it becomes a contrivance. Instead of feeling like a natural occurrence inside the fictional world, it’ll feel like an arbitrary decision you made.

It Prevents Clashes & Conflicts

It’s always possible for some elements to undermine others. If you create a mystical enchanted forest where the trees seem to whisper to each other, and then you add denizens that look like little clowns, that will ruin the mysterious atmosphere you are trying to establish.

That’s a pretty obvious example, but this can happen in many ways that may not always be obvious. Maybe your cosmic horror world depends on the helplessness of the humans there, but you end up adding a powerful benevolent AI that makes it seem like they aren’t helpless. Perhaps you want a feel-good world, but you end up adding something too dark. You could depict magical and mystical monks only to explain their magic with some midi-chlorians.

A theme can’t entirely prevent you from inserting something out of place. However, it gives you a plan for the overall impression you want to create in your world. Then when you add something, you can be more intentional about whether it will help you create that impression or work against it. This will reduce your chance of making choices that clash with each other.

It Attracts a Dedicated Audience

When Mythcreants discusses storytelling, we focus on universal principles that help us broaden our audience. That doesn’t mean taste isn’t a strong factor in audience engagement. Defining every taste out there would be impossible, but we can avoid creating worlds that require audiences to have first one taste and then a completely different one.

If someone picks up a Discworld book and doesn’t find it funny or otherwise engaging, they’re unlikely to grab another one regardless of what’s in it. They’ll guess that it’s not for them, even if it is. If someone picks up a Discworld book and ends up laughing at every line as they fall in love with the characters, they’re very likely to grab another from the anthology. If that book doesn’t have what they enjoyed the first time, they’ll be really disappointed with the series. If the series switched the tastes it was catering to, it would alienate everyone.

You’ll need an enthusiastic audience that is willing to pitch your world to their friends. If your world feels different every time they turn the page, that’s much less likely to happen. Keeping to a theme will help you cater to a specific audience that absolutely loves what you’re putting out.

Allowing Variation and Contrast

A woman stands with a horse that has glowing blue circuitry, in front a city with a church steeple and great gears
Image by Tithi Luadthong on Shutterstock

A theme constrains your choices. That’s the whole point; it helps you make worldbuilding choices that synergize. But that doesn’t mean you can’t do interesting things.

Including More Variation With a Broad Theme

First, you may decide to get your theme loose and broad. For instance, a standard urban fantasy story has the modern world plus a huge range of fantasy and folklore elements. While this will make the world less memorable than it could be, it allows more variety.

In some situations, variety is particularly beneficial. For instance, if the masquerade is broken and you want to show how creatures integrate into real world society, you can keep generating novelty by bringing in a huge range of magical beings and show the unique needs of each group. In a different world, you might choose a similarly broad theme so you can make the places within it highly varied. That way your traveling adventurers have lots of different things to discover.

On the other hand, narrowing that down helps the world stand out. This is why the TV show Teen Wolf focuses on werewolves and other were creatures. It sometimes branches out with more theme-breaking elements, but it never includes other urban fantasy staples, such as vampires. When we think of Teen Wolf, we have a strong impression of teenagers transforming into animal-inspired monsters.

While a broad theme is less likely to impress audiences, it can still boost believability and improve their experience. While there may be some cases, such as for the MCU, where having even a broad theme might not be worth the tradeoff, those cases are pretty rare. Instead, it’s more likely that you’ll want to design a theme that includes contrast.

Including Contrast in Your Theme

Themes can absolutely include contrast. In fact, it often helps the world stand out. But if you simply plop contrasting elements in the same setting without thinking through how they coexist, you could give your audience cognitive dissonance that reduces their enjoyment.

Let’s take an example of a world with contrast: the Firefly setting. This scifi western has contrasting aesthetics from different genres. Sometimes characters use spaceships and laser guns, sometimes they ride horses and wield pistols. In turn, that suggests two different technology levels. The presence of these contrasting world elements is explained by differences in wealth.

The inner planets of the solar system are wealthy. That means lots of resources went into terraforming those planets, turning them into paradises. That wealth also went into building huge cities and giving everyone the best technology. The outer planets have much less wealth. Cheaper terraforming led to dry planets that are harder to live on. These are largely rural, and they don’t have the infrastructure to support as much advanced technology. When there aren’t roads, riding a horse is often more practical than using wheels.

Now imagine if everyone in a glamorous high-tech city rode horses over the streets rather than getting in a constructed vehicle, without any explanation for their choice of ride. Or people riding horses over a dusty landscape suddenly pulled out laser guns, without any explanation for how they got that technology. That’s what worldbuilders are doing when they break their theme.

If Firefly included more contrasting features, such as fantasy and cosmic horror elements, it wouldn’t be impossible to explain them. But it would still start to break down the unified impression that the theme has created. Currently, it’s defined by its technology divide. If fantasy and horror were added, how could we sum up this world in a few words?

Regardless of how much variety and contrast you’d like your world to have, you can’t include everything under the sun without making your audience scratch their heads.


Crafting an evocative world is much like crafting a beautiful painting. Each art piece in this article uses a limited color palette with a repeating set of shapes and textures. That’s what creates a cohesive look and makes it pleasing to the eye.

Need an editor? We’ve recently cleared out our waiting list. Put in your order while our availability lasts!

Jump to Comments