Underfiction
Any story.
You in it.
Literary prose, hand-painted worlds, real stakes. Open the first scene in your browser — no install.
Start a scene
Choose any setting. Add a character or two and begin. The engine writes around you and follows wherever you take it. Characters remember. Tension builds. Add new scenes or stay indefinitely. Stories can run for hours without falling apart.
How to →Or begin in a world
Crafted settings with characters, histories, and tensions already in place. Pick one and play — or use them as inspiration.
Linden Park
The Antler & Stone
The Marabou
Your story, your rules
A quiet conversation that turns into a confession. A dinner party where someone says the wrong thing. A kiss that shouldn't have happened. The writing doesn't soften the tension or steer you toward safe choices. You direct what happens — the engine follows.
Or build your own world
Write your own world from scratch — any setting, any tone, any cast of characters. Build the world. Define the people in it. Give them desires and tensions and histories. Then step inside and see what happens.
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 privacyFrequently 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?
New accounts start with free credits to try it out. 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 Opus, GPT, Grok, and Gemini. All models are accessed through Venice, a privacy-preserving inference provider that separates your identity from your prompts.
Is Underfiction uncensored?
Yes. Underfiction runs frontier models through Venice, 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.
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. We route AI inference through Venice, which 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.
How do long stories work without the AI forgetting?
Underfiction uses a scene-based architecture. Each scene has its own context. When a scene ends, it gets summarized and the context carries forward into the next scene. Stories can run for dozens of scenes without the model losing track of characters or plot.