About Castfic

Last updated 2026-10-30 · by the Castfic team

In short: Castfic is a rehearsal room for your original characters. You cast 2–4 of them into a trope, and each one is played on its own — it sees only its own card, its secret and what has been said aloud. A director keeps the scene moving toward the ending you chose, and one click turns the transcript into prose or a screenplay.

Why play each character separately?

When one AI writes a whole scene, every character knows everything: the shy one suddenly reveals the twist, and everyone sounds the same. In Castfic a character can't leak a secret it was never told. That is what makes misunderstandings, slow burns and confessions land — the things fanfic writers actually come for.

How a scene works

1. Cast: write a short card for each character — personality, how they talk, what they want, and a secret.
2. Set up: pick a trope (coffee shop AU, enemies to lovers, fake dating…), a setting and the ending beat.
3. Direct: the scene runs 8 rounds. Between rounds you can whisper a private note to one character, choose who speaks first, ask for two suggested directions, or redo the last round.
4. Keep it: rewrite as prose (sweet, angst, comedy or AO3-style) or as a Fountain screenplay, export, and each character's memory of the scene is saved to their card for next time.

How we tested it

The scene on the home page is real, unedited output (“Coffee shop AU · Rainy Tuesday”, generated 2026-10-30). Every change is checked against the same sample cast: do secrets stay hidden until the right moment, do voices stay distinct, and does the scene reach the chosen ending? Numbers are on the Facts page.

What it can't do (yet)

• Scenes are short — 8 rounds, about one chapter beat. Long stories are built scene by scene, with memories carrying over.
• No preset canon characters and no explicit content. Write your own OCs, or your own take on a fan character (Disney, Marvel, Nintendo and Pokémon characters excepted).
• AI can still be inconsistent; the redo and director's note exist for that.

Contact

Ideas, bugs or press: hello@castfic.com.