REGENCY
Ashworth End
A manor, a moor, and a season of engagements nobody intends to keep.
She burned the letter and kept the ribbon, which told him everything the letter had not.
Underfiction
Any story.
You in it.
Interactive fiction in literary prose, under your direction.
Free to start. No signup, no card, no subscription.
YOU
Make him almost say it — then the doorbell.
That’s the whole loop. You direct — in the scene or from outside it — and the engine writes prose you’d actually want to read back. No prompt engineering, no settings. Short, specific direction wins.
Begin in a world
Crafted settings with characters, histories, and tensions already in place — or start from a blank page. The world is a spark, not a cage.
CONTEMPORARY
Linden Park
A house full of family, money, and things nobody says by the pool.
The pool light went out at midnight. Nobody moved to fix it.
FANTASY
The Antler & Stone
A tavern at the forest's edge, where every traveler owes something.
The tavern went quiet the way a forest does — all at once, and for a reason.
SCI-FI
The Marabou
A freighter three weeks from anywhere, a crew of eight, one secret too many.
Three weeks out, someone began leaving flowers in the airlock.
Nothing is off limits.
Literary fiction runs on violence, desire, and moral complexity. An engine that refuses them can’t write fiction worth reading. Underfiction runs frontier models — Fable, Opus, GPT, Grok, Gemini — and they follow your direction. No filters, no refusals, no moralizing.
Push the story. The best scenes come from risks.
You’re the director
Act
“She opens the letter.”
Narrate what your character does, says, thinks. The engine writes the scene around you.
Speak as anyone
“Have the captain lie about the fuel.”
Put words in any mouth, thoughts in any head. Introduce events. Change the weather.
Step outside
“Slow down. Make this scene tense.”
Give the narrator instructions directly, like a director between takes. The story obeys.
Chapter nine remembers chapter two
Scenes work like chapters. When one ends it’s summarized and the story carries forward — a promise made early still binds late. Stories run for dozens of scenes without falling apart, and the remembering is free: you only pay for the prose itself.
How to play →Give the story a face
Generate portraits for your characters and paintings of your scenes, right where the story happens. Set a scene image as the reader’s backdrop. Then set any image in motion — a look held a moment too long, weather rolling over the moor.
Made inside the story. Kept inside the story.
Private by design
Your stories stay on your device unless you enable sync, in which case we store encrypted copies for your account. Your identity is separated from model requests at the infrastructure level.
Learn more about privacyCredits, not subscriptions
Frontier models are expensive to run. Credits let us offer them without subscriptions, ads, or compromises on model quality. You buy words when you want them; the story never expires.
Frequently asked questions
What is Underfiction?
Underfiction is an AI-powered interactive fiction platform. You choose or create a world, set a scene, and write collaboratively with frontier language models that produce literary-quality prose — not chatbot replies.
Is Underfiction free?
You can open a scene in the browser and start writing without an account. New accounts get free credits when you confirm your email. After that, you pay only for the AI tokens you use — no subscriptions, no ads, no free tier subsidized by your data.
What AI models does Underfiction use?
Underfiction offers Fable, Opus, GPT, Grok, and Gemini. All models are accessed through a privacy-preserving inference layer that separates your identity from your prompts. You can switch models mid-scene.
Is Underfiction uncensored?
Yes. Underfiction runs frontier models through an inference layer where they follow creative direction more faithfully than they do through official APIs. No content filters, no refusals, no moralizing. Literary fiction routinely contains violence, desire, and moral complexity — an AI that can't engage with those elements can't write fiction worth reading.
Can Underfiction generate images and video?
Yes. You can generate portraits for your characters and images of your scenes, set a scene image as the reader background, and animate any image into a short video clip — all inside the story, paid with the same credits as prose.
Does Underfiction store my stories?
By default, stories stay on your device. If you enable story sync, we store encrypted story blobs on our servers so they can move across devices. AI inference is routed through a layer that separates your identity from your prompt before it reaches the model provider.
How is Underfiction different from Character.AI?
Character.AI is a social platform with community characters and strict content filters. Underfiction is a private writing tool — no public feeds, optional encrypted sync, and frontier models that produce literary prose instead of chatbot dialogue.
Can I create my own characters and worlds?
Yes. You can build a world from scratch — any setting, any tone, any cast of characters. Define their personalities, desires, tensions, and histories, then step inside and see what happens.
Can I import characters from SillyTavern or other apps?
Yes. Underfiction imports Tavern V2 character cards as PNG or JSON — the format used by SillyTavern, Chub, and most character-card libraries — and world books as JSON. Import a card from the Characters page and start a scene with it.
How do long stories work without the AI forgetting?
Underfiction uses a scene-based architecture. Scenes work like chapters: each has its own context, and when a scene ends it gets summarized and carried forward. Stories can run for dozens of scenes without the model losing track of characters or plot — and summaries are free.