What Dreams May Die? How to Game Cosmic Horror

We stand knee-deep in the spooky season, and “horror” is the word on everyone’s lips. GMs clamour to inject terror into their campaigns, and players long to be thoroughly terrified. The question, however, is how. Horror has been a staple of the TTRPG scene since its very inception, and of all the different flavours of horror that have influenced the hobby, the greatest and most terrifying is cosmic horror. 

Horror is a tricky genre. Mechanically, it’s very similar to comedy: Both comedy and horror exaggerate the absurdities of reality, relying on perfect timing and pacing to do so. In comedy, these absurdities divert from the expectation of mundanity, while in horror these absurdities introduce risk of danger and death. 

Funny stuff. 

Adapting cosmic horror to an RPG setting is especially tough. Cosmic horror is a genre defined by humanity’s insignificance in the face of an uncaring universe. This is a genre that places huge emphasis on the impotence mentioned earlier, as powerless mortals fruitlessly wrestle with incomprehensibly large, powerful, and dangerous forces. Your nat 20s and four-part multi-attack builds mean nothing to Azathoth, the Daemon-Sultan Lord of All Things. 

The thing is, many RPG systems are not equipped to deal with this level of impotence. Many modern TTRPGs place the players at the centre of the universe, where their decisions shape the setting and surroundings. This isn’t just a D&D problem: You can feel shades of this in Pathfinder, Blades in the Dark, Lancer, and any game where competence and agency are key features of the player’s role. 

Furthermore, TTRPGs primarily rely on verbal/written descriptions to express their settings, and writing cosmic horror is bloody difficult. Lovecraft - the pioneer of the genre and a major influence on the TTRPG scene as a whole - set a standard for comprehending the incomprehensible that few authors have been able to imitate. In my experience it goes down one of two routes:

“The indescribable horror was so horrifying and indescribable it horrifies me merely to describe it!”

Or 

“The tentacle was big and tentacley, and covered in slime, and it had teeth, and the teeth were covered in slime, and the tentacles also had teeth covered in slime!”

Neither are especially scary. 

In this article, we’ll look at some of the elements I have successfully used in the past to introduce a pervading sense of cosmic horror to my home games. Your mileage may vary regarding on how effective you find these elements - horror is a pretty broad genre, after all, and everyone has a different threshold for fear¹ - but, with the right combination of elements, you can use these tips to terrify your players. 

A Note on the “Cosmic” 

“Cosmic horror”, as a name, evokes a very specific vibe. “Cosmic” evokes the blackness of space, and as such the most commonly-understood tropes of cosmic horror are found in the depths of space. However, cosmic horror refers more to the scale of the horror than its setting. 

The colossal size of the cosmic is juxtaposed against the tiny, meaningless nature of humanity, and it is this juxtaposition that results in horror. This also doesn’t necessarily mean that the monsters of cosmic horror need to be physically massive: Godzilla isn’t necessarily cosmically horrifying, despite his size, while Junji Ito’s Uzumaki finds cosmic horror in something as small and insignificant as a woman’s cochlea. 

Throughout this blog post I’ll allude to cosmic horrors that, on the face of it at least, don’t seem especially cosmic. The idea here is more to suggest how one can introduce the feel of cosmic horror to their games, looking at the masters of the craft and working out how elements of their work can be adapted for a TTRPG medium. 

Keep It Vague 

I’ve already alluded to the main hurdle that writers have when introducing cosmic horror elements to their stories: It’s either unknowable, or it’s slime. While we can all agree that slime is yucky, it’s not especially frightening. 

When introducing cosmic horror to my games, I like to start by describing things in small but evocative details while my players frantically try to connect the dots. This encourages your players to spook themselves: It’s often been pointed out that people are afraid of the unknown, so your job as GM is to foster that fear. 

“You stand before the door. The paint is flaked and cracked, with deep, jagged gouges in the wood. On the other side you hear the shuffling, an uneven dragging sound of flesh on stone. Chains rattle, and a thick, sulfurous stench hangs thick in the air.” 

Right. What can we infer about the monster on the other side of the door?

• It probably has claws, or at the very least it has sharp nails; 

• It shuffles as it moves, and there are chains in the room; 

• It - or something in the room - smells like sulphur. 

Here, your players will start speculating. Based on the wider context of the encounter (setting, goal, etc.) they might guess that a zombie or mummy lurks behind the door; Perhaps it is some great, awful beast, broken loose of its chains; the sulfurous smell might indicate a demon, or some horrid, stinking creature… 

We actually do see glimpses of this in Lovecraft’s own writing. Cthulhu, his most famous creation, is often depicted as a sort of squid-faced man-dragon. However, in The Call of Cthulhu, Cthulhu is described thusly: 

“It seemed to be a sort of monster, or symbol representing a monster, of a form which only a diseased fancy could conceive. If I say that my somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature, I shall not be unfaithful to the spirit of the thing. A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings.” 

Look at how vague that description is! Cthulhu is sort of like an octopus, and sort of like a dragon, and sort of like a human, but more than anything it’s a symbol, an idea, a madman’s hallucination of a monster. This feels less like a description, and more like someone frantically attempting a description. And, somewhere amongst that vagueness, the mind begins to percolate something truly horrifying… 

Impotence

Mind out of the gutter, people. 

TTRPGs live and die on player agency. However, horror - and cosmic horror in particular - requires its victims to feel a sense of helplessness. Helplessness is invariably born from a lack of agency, a moment in which our power is taken from us, where the only choice we are permitted to make is run or die. 

This is anathema to most TTRPG players, GMs, and designers. For many people in the hobby, the concept of player choice is the golden standard, the axel around which the game spins. Getting players to sacrifice their agency is difficult, and requires either incredible timing, strong worldbuilding, pre-game conversations, or some combination of the three. 

Perhaps your players are stranded - their only hope of safety is to make a break for the nearest town, a five mile walk away. It’s not too far, sure… But there’s something outside. The players can’t see it. They can’t confirm what it is. But they know it’s dangerous. They know it’s big². They are helpless in the face of this threat, completely at the whims of whatever seeks to devour them on the other side of that door. They are scared. 

Depending on the game you're running, your players will most likely want to immediately rush out and fight their foe. This is an important moment, as it establishes a) the stakes of the matter at hand, and b) what the players can actually do. To ramp up that feeling of helplessness, their initial attacks against their unknowable foe should do literally nothing. Their weapons don't leave a mark, their actions are so futile that the creature seems to barely even register them. The creature might retaliate, but it should do so idly. There should be no malice, no forethought in its actions. It doesn't hate the players, it doesn't want to eat them or destroy them. It is just trying to swat them away, like you might a particularly adventurous mosquito.

Such actions seldom work out for the mosquito, of course.

Simulating the Unknown: The Phantom Roll

So we know that our players need to be confronted with the unknown, and we know that they must be unable to do anything about it. But how exactly do we go about creating a scenario in which both of these things are true? 

We introduce the Phantom Roll. 

This is an idea that I first encountered in Dragon Magazine #210. In his article Who's Afraid of the Big Bad Ghost, author Spike Y. Jones introduces the idea of making secret rolls behind the GM screen, making some notes, and then carrying on as normal. The players will inevitably notice this. An especially paranoid player may even ask what you’re rolling for. You reply “Hmm? Oh. Nothing.” 

Little do they know, you’re telling the truth. 

You’re not rolling for anything in particular. You’re not writing anything of importance down. But your players don’t know that, and it makes them jumpy. For all they know, you just rolled on an RNG table and have generated a horde of slathering night terrors ready to pounce on them from the darkness. Like in our earlier example, they begin to speculate - this time on a meta level - on the threats that go bump in the night. 

Phantom Rolls simulate the experience of receiving a bad vibe, the feeling that something is plotting against you. Phantom Rolls foster paranoia. They work well in all forms of horror gameplay, to be sure, but they work especially well in a genre built on a fear of the unknown. Phantom Rolls keep your players on the back foot, making them feel like they're on the outside of something, as though they are at the whims of a powerful, omnipresent, and uncaring god³.

Perhaps it’s a little unethical, playing mind games on your players: But GM screens exist for a reason, to create a barrier between the GM’s plans and the player’s experiences. 

Go on. Get in their heads. Make ‘em sweat. 

Conclusion 

From the earliest days of the hobby, cosmic horror has been a primary influence on the TTRPG medium. Gygax made no illusions as to his influences, and the original D&D Appendix N is littered with references to Lovecraft’s works. Call of Cthulhu itself is among the most influential TTRPGs on the market. And yet, this illusive genre is surprisingly hard to capture within gameplay. 

To achieve powerful, effective cosmic horror in your games, you will require a combination of good writing, great timing, creative setpieces, and a fair amount of mind games. Arguably this is true of all GMing, but because cosmic horror is so easy to get wrong - and so catastrophically funny when it does go wrong - a GM must expend extra diligence when trying to scare their players to the core. 

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¹ It’s also worth mentioning that not all horror seeks just to scare its audience. Consider titles like Saw or Videodrome, which seek to disgust their audiences, or Freddy Vs. Jason or the Terrifier franchise, where the horror on display acts more like a punchline than it does a genuine scare. Cosmic horror is actually unusual in that, rather than creating a sense of terror, it generally seeks to foster a sense of existential dread.

² I recommend Stephen King’s The Mist or the incredible Dr. Who episode Midnight for inspiration on how to run this kind of encounter.

³ Otherwise known as a "GM".