All About Cosmic Horror (How to Write it Like a Pro)

All about cosmic horror

Cosmic horror is one of the older horror genres by today’s standards, but it has inspired many books and movies and continues to do so. Writers like Stephen King and Clive Barker draw heavily from the genre and there are many dedicated authors who will only write Lovecraftian-style books.

To write cosmic horror have your characters deal with themes of madness and the unexplainable. Choose remote locations or even other dimensions. The underlying theme in cosmic horror stories is that the universe is large and predatory and humans are small and weak with limited understanding.

Cosmic horror is a broad and fascinating genre. If you go down this particular rabbit hole you can get lost for days. No one can say with certainty what exactly a cosmic horror story should be, but here is my humble attempt to explain them.

What is Cosmic Horror?

Cosmic horror is a subgenre of speculative fiction. It can be found in various media, including film, literature, and video games.

In many instances, cosmic horror stories take place in the real world. However, they also frequently feature science fiction and fantasy elements, such as extraterrestrial life forms or otherworldly forces threatening humanity.

The main theme in cosmic horror stories is often an attempt to explore the human condition by examining what would happen if the universe were fundamentally malignant. This can be seen through characters driven mad by their experiences with these hostile forces and stories that explore the idea that we are not alone in the universe.

Some of the best-known examples of this genre include H. P. Lovecraft’s Cthulhu Mythos stories, which include The Call of Cthulhu; Arthur Machen’s The Great God Pan; Frank Belknap Long’s The Space Eaters; Clark Ashton Smith’s A Rendezvous in Averoigne; Donald Wandrei’s The Wanderer; and Fritz Leiber’s Conjure Wife.

Themes in Cosmic Horror

While some alien-fiend horror is a prerequisite for a Cosmic Horror story, many themes make up the cosmic horror genre: mindlessness, mutants, telepathy, and more.

The idea behind these themes is usually (but not always) that collectively they chip away at our sense of security and belief in ourselves.

As we uncover further horrors in the universe, we become more bleak, weary, and disillusioned with the reality around us where something like that could exist. They help to retreat from reality and push us into the story. Here are themes in cosmic horror.


Cosmic horror tends to be set in remote locations removed from society. Whether it’s an isolated island or an abandoned house on an isolated mountain, there’s usually no escape from whatever horrors are lurking there.

The idea is that this place has been cut off from humanity for so long — whether by physical distance or by some other means — that its inhabitants have developed strange customs and practices that seem utterly alien to us.

This isolation also works as a metaphor for our insignificance in the face of the cosmos, which makes those places even more unsettling than they would be otherwise.


Time is often an important theme in cosmic horror stories because it can show how insignificant humanity is compared to other beings in the universe.

A good example of this theme comes from author H.P. Lovecraft’s short story “The Call of Cthulhu.” This story centres on a cult that worships Cthulhu, an ancient godlike being who sleeps beneath the ocean, waiting for someone to awaken him so he can rule over Earth again (Lovecraft). The cultists practice strange rituals such as sacrificing animals and humans by drowning them in underground wells (Lovecraft).

This story also portrays humans as being ruled by fear when.


The human mind is often a central theme in cosmic horror stories, where characters explore the boundaries of their minds and their understanding of reality.

Characters may realize they have limited knowledge about their physical environment and question whether they are truly sane or not.

This theme can be explored through dreams, hallucinations, or drug use by characters who experience some form of mental break.

Human Inadequacy

In cosmic horror fiction, humans are insignificant compared to the universe as a whole. We are too small and weak to do anything about our fate.

We are doomed from the start due to our place in this world, as well as our nature as humans, being flawed and corruptible.

We are not perfect beings like gods but rather mere mortals with human flaws such as greed or lust for power. These cause us to commit evil deeds that bring nothing but death and destruction upon ourselves.

Creation of the Unknown

Cosmic horror is often about the unknown, and there are several ways to create this sense of mystery and fear.

First, there is a sense of isolation. If the protagonist is isolated from their peers, they may feel more vulnerable and exposed to whatever horrors are in space.

Lovecraft uses this technique throughout his stories: his characters often find themselves on their own in remote locations far away from civilization.

Tropes in Cosmic Horror

In a Horror story, the principal characters are almost always in a state of denial about their situation. It’s only when they are close to death that they realize that they have been living in a fantasy world – sometimes literally.

This shock and shift in perspective create a sudden change in the story’s tone, reflecting the new grim reality that the main character is now facing.

Here are some common tropes in cosmic horror.

Incursions From Other Dimensions

This trope refers to the idea that other dimensions or universes exist parallel to our own, and sometimes they can invade our reality through portals or other means.

This can be used as an origin story for various monsters and creatures in a setting, like demons or aliens from another planet who have arrived on Earth through these portals.

It can also be used as a source for strange phenomena like ghosts who have crossed over into our world from another dimension or dimension-travelling sorcerers who use magic spells to travel between dimensions at will. In some cases, these incursions are relatively benign (like ghosts), while others represent a serious threat (like demons).


Cosmic horrors tend to be incomprehensible and alien enough that even when you see them, you still don’t get what they’re about — their appearance and behaviour are designed to make us feel confused, disgusted, and disturbed at how different they are from us (or how much like us).


In many cases, the characters are trapped in prison (either literal or metaphorical) by some force or being for most or all of the story.

Often this imprisonment is not easily escaped. In some cases, it may even appear impossible to escape (this can be because the entity knows that no one could escape from it regardless of their efforts or because it wants them trapped).

In other cases, there may be hope for escape, but it requires great sacrifice on behalf of the protagonist(s). This can also lead to an Unwinnable situation if they choose incorrectly or too late in their escape attempts.

The Eldritch Abomination

This trope is about mysterious alien beings or forces beyond human comprehension, often threatening to destroy humanity or enslave it forever.

These entities usually have strange physical forms (such as tentacles) and don’t speak any human language. Examples include Cthulhu, Yog-Sothoth, and Shub Niggurath.

How to write cosmic horror

Cosmic horror is all about creating a sense of unease and dread. The best way to do this is to focus on the unknown or the unknowable. What is lurking in the shadows? What secrets does the universe hold?

Use atmosphere and setting to create a sense of unease. A good cosmic horror story will have a strong sense of place, whether it’s an otherworldly landscape or a dark and foreboding city.

Also, cosmic horror is often about characters who are struggling to maintain their sanity in the face of the horrific. This can be done by depicting characters who are already on the edge of madness or by slowly driving them insane over the course of the story.

What makes cosmic horror scary?

  1. The unknown: Cosmic horror is all about the fear of the unknown. What is lurking in the shadows? What secrets does the universe hold? This sense of unease and dread can be very unsettling and scary for readers.
  2. The atmosphere: A good cosmic horror story will have a strong sense of place, whether it’s an otherworldly landscape or a dark and foreboding city. This creates a sense of unease and allows readers to get lost in the story.
  3. The characters: Often, cosmic horror is about characters who are struggling to maintain their sanity in the face of the horrific. This can be done by depicting characters who are already on the edge of madness or by slowly driving them insane over the course of the story. Either way, it makes for some very scary and intense reading.
  4. The themes: Cosmic horror often deals with themes of insanity, death, and existence. These are all things that can be very scary to think about, and they make for some great horror stories.
  5. The overall tone: Cosmic horror is often very dark and unsettling. This creates a feeling of unease in readers that can be quite scary.
  6. The writing style: Cosmic horror often relies on atmosphere and setting to create a sense of unease. This means that the writing style is often very descriptive and evocative. This can be great for setting the mood and getting readers into the story.
  7. The suspense: Because cosmic horror is all about the unknown, it can be very suspenseful. This makes for some great cliffhangers and edge-of-your-seat reading.
  8. The scares: Because cosmic horror is so suspenseful, it can also be very scary. This genre is not for the faint of heart, but if you’re looking for a good scare, cosmic horror is the way to go.
  9. The overall experience: Cosmic horror is a unique genre, and it can be a very rewarding experience for both writers and readers. If you’re looking for something different, cosmic horror is definitely worth checking out.

Examples of Cosmic Horror by H. P. Lovecraft

The Call of Cthulhu: This is one of the most famous examples of cosmic horror, and for a good reason. It tells the story of a man who discovers the truth about an ancient creature that is trying to take over the world. The story is full of suspense, scares, and unease, and it’s one of the best in the genre.

The Shadow Over Innsmouth: A man goes to investigate a town that is said to be cursed. He soon discovers that the townspeople are being controlled by an evil force, and they want to turn him into one of them.

The Dunwich Horror: This story follows a group of people who investigate a series of strange events that have been happening in a small town. They soon discover that a horrific creature is behind it all, and they must stop it before it destroys the world.

At the Mountains of Madness: A group of scientists travel to Antarctica to investigate some strange ruins. They discover a horrible creature left behind by an ancient race.

The Colour out of Space: A man moves to a small town in Massachusetts to start a new life. He soon discovers that a strange force is behind some of the townspeople, and they’re slowly being driven insane.

Final Thoughts

Cosmic horror is an enduring genre with a huge cult following. It is fun to write, especially if you love to write creepy stories. Now it’s over to you. Good luck.