How to Write Cosmic Horror and Unleash an Abomination

Abi Wurdeman
July 7, 2024

Remember the last time you squashed a bug, either intentionally or accidentally, whether by hand, foot, book, or windshield?

Remember how easy it was? How swift? Remember how it was so inconsequential to you that you’re not even sure if the squashing you recall actually was the last time? 

That’s cosmic horror. And in this particular example of cosmic horror, you’re the horrifying monster from an unknowable realm. That’s not a dig; it’s just a convention of the genre.

Cosmic horror brings us the same thrills and chills we’ve come to expect from other horror subgenres, but with a bonus existential crisis to drive both protagonist and reader mad.

The terrifying beings that populate this genre are evidence of a reality that’s larger, more complex, and far more threatening than the one we know—one that forces us to see that we don’t stand at the center of existence. 

We’re just carrying our crumbs through existence’s kitchen outlets like the oblivious ants we are. Small. Forgettable. Too powerless to threaten the monsters but also too worthless to spare should we become an inconvenience.

When we talk about how precious human life is, cosmic horror replies, “Sure, but like, precious to whom?” If it’s just to ourselves, does it matter?

Yes, oh my gosh, one thousand percent. Powerful or not, human beings are valuable. But cosmic horror gives us a chance to indulge the nagging fear that we aren’t.

If today is the day, let’s get to it. We’re going to cover just about everything you need to know to write a cosmic horror story, from tropes and conventions to character and plot.

First, the big question:

What is Cosmic Horror?

Cosmic horror is a subgenre of horror fiction that’s less about gore and jumpscares, more about existential dread. It taps into our fear of the unknown and unknowable, often through a blend of horror, fantasy, and science fiction elements.

The subgenre emerged in the early twentieth century as a descendant of Gothic fiction. Its themes of incomprehensible mystery were initially a reaction to the Industrial Revolution, an era that celebrated science and rationalism. 

For cosmic horror protagonists, rationalism proves worthless. They uncover a reality the human mind cannot hope to fathom—one they will never be able to control, destroy, or overcome through ingenuity. This reality is usually home to nightmares whose very existence threatens to break folks like you and me.

H.P. Lovecraft is considered the father of cosmic horror, which is why you may also hear it referred to as “Lovecraftian horror.” The man himself favored the term “weird fiction.”

Lovecraft was also an outspoken racist whose descriptions of racial minorities in his stories (and in life) betray the depth of his own fear of anyone or anything remotely unfamiliar. 

Fortunately, a century’s worth of cosmic horror stories have proven that this subgenre belongs to everyone. And in recent years, writers of color like Matt Ruff and Victor LaValle have subverted and reimagined Lovecraft’s work to comment on the Black experience in America while indulging in the genre’s most chilling conventions.

Common Elements of Cosmic Horror

A blurry, human-like being with black and blue ink pouring out of their eyes.

I think you’re getting the gist of the genre by now. In cosmic horror, there’s more to reality than we’re aware of. And whatever that “more” is, it’s bad. Bad for humanity, anyway.

But how does that play out, exactly? What tools and elements do cosmic horror writers use to drum up all that existential dread?

Let’s discuss.

The Unknown and Unknowable

In most cosmic horror stories, the protagonist discovers a layer of reality beyond human comprehension. 

This reality might involve the existence of advanced alien creatures who manipulate humanity for their own gain. Or monster-like gods who are summoned from an eldritch realm by way of an ancient artifact. 

Whatever the situation, the protagonist of the story is forced to confront the terrifying truth that there are powers at work human beings know nothing about—powers that can destroy us at the slightest whim.

Cosmic horror doesn’t just play on the chilling thought that we’re just stupid little ants, oblivious to the monstrous faucet overhead as we take a stroll in the bathroom sink.

It also steps on our fear of ignorance and grinds its sadistic foot with the suggestion that we wouldn’t be able to comprehend reality even if it were revealed to us.

We couldn’t use our reasoning to protect ourselves. Knowledge of the unknowable only leads to madness. And maybe death. Usually death.

Insignificance of Humanity

I actually like bugs. I love imagining the world through their bulbous eyes and usually leave them to enjoy their tiny lives.

But my husband and I are currently battling fruit flies. They zip around my face when I’m trying to work and make me feel like my home is dirty. So, when a fruit fly landed on the page of my book the other night, I slowly closed the cover and gave it a good squeeze. 

That’s my latest bug squashing story. I fancy myself a benevolent being and still extinguished a whole entire life just because it annoyed me. And now I share this story with you, confident you won’t judge me for it. (I am a little worried about how you’ll react to the way I treated my book.)

That’s what humans are to the unfathomable monsters in your cosmic horror novel. Best case scenario, these creatures don’t really care if your human characters live or die. They have no problem closing the metaphorical book cover should your characters irritate them, inconvenience them, or wake them from their ancient slumber.

The worst part? 

Such a squashing would have no meaningful impact on existence. Humans aren’t just powerless—we’re unimportant. In the world of cosmic horror, nothing we do matters.

Takes a little pressure off of the whole climate change thing, but that’s pretty much the only perk.

Eldritch Beings and Gods

Now, let’s talk about these ghastly creatures representing the unknown and unknowable.

In most cosmic horror stories, these monsters are eldritch abominations—terrifying beings that defy natural law. 

Some eldritch abominations are humanoid, appearing in an eerily familiar form but with physical qualities or abilities that are decidedly non-human. 

Most are grotesque monsters, hideous aliens, or even mechanical abominations created by science light years beyond our understanding.

In some cases, these beings are also gods. Deities are huge in cosmic horror. After all, what’s more unknowable than a god?

Lovecraft’s most famous abomination, a tentacle-bearded being called Cthulhu, belongs to a category of destructive god-like beings known as the Great Old Ones. That horrifying li’l clique continues to be embraced, referenced, and reimagined by modern cosmic horror writers.

It’s the same deal with the Elder Gods that appear in Lovecraft’s work. These folks actually protect humanity, so they’re kind of a breath of fresh air in the toxic atmosphere of cosmic horror. 

That said, their ancient battle with the Great Old Ones only proves human beings have no clue about the forces that hold their world together.

Descent Into Madness

In a typical cosmic horror story, the characters who discover the existence of eldritch abominations and their hidden realms of terror do not weather the revelation well.

After all, the entire point is that they’re learning things human beings are not meant to understand. Their minds can’t process it. So, if they manage to survive the story, they often end up going a bit mad.

And not only is their psyche crumbling over this terrifying new knowledge, they also have to live alone in their awareness. Who are they going to tell? Who would believe them?

The isolation drives them deeper into madness. For as grandiose and immeasurable as cosmic horror can be, it makes great use of a must-have in horror: isolating your protagonist. More on that in a bit.

Popular Tropes in Cosmic Horror

Now let’s dig into some of the most popular tropes in cosmic horror.

As is the case with all literary tropes, you don’t have to use these exact storytelling devices to write a cosmic horror story readers will love. 

But it’s worth knowing about them because fans of the genre enjoy them, look for them, and discuss them at length. They’re also effective tools for highlighting those themes of human insignificance and the terrifying nature of the unknown.   

Forbidden Knowledge

A person in a blue robe with dark, pointed fingernails holds out their hand in a "stop" gesture.

It’s not just that human beings aren’t aware of the greater forces at work. It’s that they’re not supposed to know. 

When your main character breaks through and discovers the existence of horrifying gods or stumbles into an eldritch realm, it’s a violation. 

And whatever follows is punishment for their curiosity. 

As we’ll discuss later, cosmic horror protagonists are often knowledge-seekers like scientists, historians, or travelers. They love science and trust human reasoning.

What they learn is that they’re actually not that bright in comparison to the greater beings out there, and honestly, ignorance was bliss.

Cults, secret societies, and other creepy little occult-obsessed gangs are common in this genre. They’re often the keepers of forbidden knowledge and ancient, wrath-conjuring artifacts. That brings us to our next trope.

Ancient Texts and Artifacts

While humanity as a whole is happily unaware of the horrors lurking beneath the reality they know, there may still be tangible evidence of the truth.

Many cosmic horror stories feature ancient texts and/or artifacts that hint at the existence of god-like beings and can even free them from captivity or beckon them to the human world.

Sometimes it’s a villainous worshiper who summons the gods. Sometimes it’s the oblivious protagonist who thinks they’re just doing research like the intellectual they are.

Whoever uses them and however they do it, these ancient objects act as a highway between the abomination’s house and ours. 


As you know by now, psychological isolation is a common theme in this genre.

The main character(s) is the only one who knows the truth. It’s a truth they can’t share for fear of being labeled insane, which means it’s up to them alone to confront this terror and try to protect the world they know.

Often, a cosmic horror writer emphasizes this theme by also isolating the character physically. This person might be stranded in an unfamiliar realm, confronting eldritch abominations only they can see, or battling terrifying creatures while floating in space, Alien-style.

Unreliable Narrators

Many of these stories are written in the voice of a character who’s giving their account of the horrors they’ve witnessed. A cosmic horror story might be framed as a confessional, an epistolary tale (that’s a fancy way of saying it’s written as a letter), or a conversation between characters.

However it’s framed, the narrator may come off as a bit unreliable. This is someone who’s seen some crazy stuff that utterly destroyed their psyche.

They might seem erratic or deeply disturbed. They probably even admit to feeling insane.

This leaves both fictional listeners and real-life readers wondering what’s true and what’s nonsense created by the thunderstorm inside their damaged mind.

Crafting a Cosmic Horror Setting

Now, to really drive home the existential nightmare that is cosmic horror, we need to build an atmosphere of absolute dread.

As you read cosmic horror (you should if you intend to write it), you’ll learn that you can set your story in just about any location or time you wish. 

Your main character’s normal world might be totally ordinary, like a little town in Middle America where not much happens. Or maybe your readers first meet your characters on a space expedition 1,300 years in the future. Perhaps horror finds your protagonist on the streets of Elizabethan London.

Whatever you choose, decide how you’re going to find the creep factor of that location. This includes using elements of the setting to create a sense of foreboding or hopelessness, as well as allowing the supernatural to influence the physical space in chilling ways.

Beyond the main character’s normal world, you’ll also want to explore the possibilities for other realms. This includes nightmares and, of course, the planes of existence where your monsters reside. These are known as eldritch locations, and you want to make those joints as eerie, sinister, and unnatural as you can.

For a little extra help, check out Doug’s tips on writing a horror setting.

Developing Characters in Cosmic Horror

A scientist looks at something in a test tube.

As with any story, you’ll need to develop a protagonist/antagonist relationship for your cosmic horror.

In this genre, protagonists tend to be rational, curious people, and these traits are often reflected in the way they spend their time. They might be scholars, antiquarians, scientists, or travelers. 

Or they might just be someone who has a good motive for investigating strange occurrences, like the fact that their cousin is the third horticulturist to disappear this week.

The antagonist is, of course, the monster or reality they stumble upon. 

What’s notable about the protagonist/antagonist dynamic in cosmic horror, however, is that the antagonist rarely targets the main character, at least not as a true opponent. From your antagonist’s perspective, this person is too weak and stupid to pose any real threat. 

As far as external conflicts go, this isn’t character vs. character but character vs. the supernatural. The protagonist fights to survive against a force they’re powerless to defeat in any real sense. The force itself is destructive by nature and indifferent toward the main character.

And just like in any character vs. the supernatural storyline, you’ll want to really draw out your protagonist’s humanity. 

What do they fear? What are their weaknesses? What mistakes do they inevitably make? How do these qualities epitomize human frailty—or maybe even a bit of human resilience—in the face of terror?

For more guidance on writing horror characters, check out this article.

Writing Cosmic Horror Plots

Like any narrative, a cosmic horror story centers around a conflict that just keeps getting worse as the tale progresses.

Also like any other narrative, you’ll want to keep the relationship between internal and external conflict in mind as you write your story.

While the external conflict steals the show—what with the towering, tentacled beasts and all—the internal conflict is the one that drives home those existential themes of powerlessness, human hubris, and the gift of ignorance. 

So allow the inner conflict to continuously make the external conflict even worse, and vice versa. 

Does your character’s dogged commitment to science in the face of otherworldly forces get them into more trouble? Does that trouble throw them into an identity crisis, questioning everything they once knew to be true?

As for the ending, it probably won’t be a good one. I know it’s your story and you still have to write the thing, but cosmic horror almost always ends in tragedy. The main character dies or ends up isolated in their madness.

You’ll occasionally find a cosmic horror novel or short story that has a bittersweet ending or even a happy ending in the sense that the world hasn’t been destroyed and the important characters are still alive. Or maybe your protagonist is so broken they think things are okay because their brains can’t process the extradimensional rift where their town used to be.

Even then, whatever “fix” the main character has managed to pull off isn’t permanent. The monsters will rise again.

For more horror writing tips, click here.

Examples of Cosmic Horror

If you want to write cosmic horror, you’ll need to read a lot of it. If you need a few suggestions for where to start, I can help.

Considering that the genre is partly known as Lovecraftian horror, many writers choose to start with Lovecraft. One of his most famous works is a short story called “The Call of Cthulhu,” and reading that one will give you some handy context and language for exploring the world of cosmic horror.

But, as I mentioned before, Lovecraft’s work contains overt racism. If you read, read with care. And if you’re not up for it, you can research how his stories defined the genre and focus your reading (and watching) energy on works like these:

Agents of Dreamland - This novel draws from Lovecraft’s work and features occult intelligence agents and the threat of a fungal apocalypse. Not sure what else you could want. 

Lovecraft Country - Author Matt Ruff confronts the intersection of Lovecraftian horror and racism with this story about a Black science fiction fan in the Jim Crow era.

Alien - This one is a little more controversial in terms of categorization. While it doesn’t fit perfectly into the Lovecraftian version of cosmic horror, it incorporates some of the genre’s key elements like obsession with knowledge and an unknown, existential threat.

Basically, a commercial space crew stumbles upon intelligent life that’s looking for a face to snuggle. They end up fighting for their lives, alone in the vast universe as they battle a powerful, indifferent monster. 

Bonus Writing Tip

Hands typing on a dark laptop in a dark room.

At this point, you know how to write characters and abominations that will reveal human limitations in the most chilling way possible.

You know the genre’s most common tropes and how those tropes create the spine-tingling experience readers crave.

And I know you know how to squash a bug.

You’re ready to start writing the kind of cosmic horror story that will give your readers nightmares for weeks. But I’d like to offer one final suggestion.

Write your story with Dabble. If you’re not familiar with it, Dabble is an all-in-one writing tool that simplifies and streamlines every phase of the process, from brainstorming and plotting to drafting and revising.

See all your plot elements at a glance in the Plot Grid. Create a worldbuilding bible that’s just one click away in Story Notes. Craft character profiles, leave comments as you edit, and much more. There’s even a horror template you can snag right here.

The best part is, you can try it before you buy it. You don’t even have to enter a credit card, so there’s no risk of accidental charges. Just click this link and get immediate access to every single feature, free for 14 days.

Now get writing. The world is waiting for your nightmare.

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.