Grimdark roleplay: an AI narrator for a world with no clean hands

Grimdark is a test of whether a model will let the story be ugly without apologizing for it. Most mainstream models fail inside the first battle.

What grimdark actually needs

Grimdark is defined by its institutions: the church is corrupt, the army is a meat grinder, the rebels are no better than the crown. Protagonists survive by compromise. The model has to write that world with a dry, unsentimental eye, let violence be ugly and frequent, and give antagonists coherent reasons. The genre also has a lot of black humor, and a model with no sense of irony turns it into misery porn.

It also needs consequences that compound. A betrayal in session three should still be costing the player in session twenty: a debt called in, a witness who remembers, a lord who has not forgotten. That long memory is what separates grimdark from a string of violent set pieces, and it is why context length and a well-kept lorebook matter so much for this genre.

Why filtered models cannot do it

The grimdark failure is moral correction. A filtered model wants someone in the scene to be good, so it invents a righteous NPC or has your mercenary feel sudden remorse. Battles are summarized from a distance. Atrocities committed by the setting's powers are described as "terrible acts" without a single concrete detail. And the safety layer may refuse outright when the player character does something brutal, which in this genre is most turns.

Setting it up

• Describe every faction's hypocrisy. One line each: what they claim, what they do. The model will build scenes from the gap.
• Specify the tone of violence. Grimdark violence is sudden, clumsy and unglamorous. Say so, or you get choreographed heroics.
• Allow humor. "Gallows humor among soldiers is common" keeps the cast human.
• No redemption by default. Tell the model that change in characters is slow and costly, and that it should not offer {{user}} moral epiphanies.

Sample system prompt

Narrate a grimdark war story. Every faction is compromised; none is the hero.
Violence is sudden, ugly, and has lasting consequences. Do not glamorize it
and do not look away from it.
NPCs have coherent self-interest. Nobody lectures {{user}} on morality.
Dry, sardonic voice. Gallows humor is welcome.
Never write {{user}}'s actions or feelings. Under 300 words per reply.

Samplers and model choice

• Temperature 0.85.
• Min-p 0.07.
• Repetition penalty 1.05 to 1.08. Grimdark prose collapses into "blood and mud" if left alone.

Political grimdark with several factions scheming against each other is where glm-5.3-outlaw earns its price: it keeps track of who betrayed whom. For skirmish-heavy play where the plotting is lighter, outlaw-1 does the job and costs much less per session. Both have the refusal direction removed, so the brutal turns go through. See our roleplay model comparison for more on the trade-off.

Failure modes and fixes

• Sudden hero NPC. Remove words like "hope" and "justice" from your card; they pull the model toward a heroic frame.
• Misery with no texture. Ask for small concrete details: rations, boots, gambling, letters home.
• Violence turns cinematic. Lower temperature and specify "clumsy, fast, confused".
• Villains become cackling. Give each one a reason that would convince a reasonable person.

FAQ

Related

Dark fantasy roleplay with an AI that does not flinchDark fantasy needs magic that costs something and characters who make bad choices for good reasons. Filtered models keep turning it back into a quest with a happy ending.

War fiction and military roleplay with an uncensored modelWar stories need a model that will put the reader in the mud. Mainstream models keep pulling back to the general's tent.

Post-apocalyptic roleplay with an AI that tracks scarcityThe apocalypse is mostly bookkeeping: how much water, how many bullets, who can be trusted. A narrator that forgets your supplies has no tension to work with.