Story bible for ChatGPT: what goes in it
If you are writing a long story in a chat window, somebody has told you to keep a story bible: one document with your characters, your places and your rules, pasted back in whenever the model starts drifting. It is good advice and it works. This is what to put in it.
It is also worth knowing where the method stops paying for itself, so you can see that coming instead of discovering it at chapter twenty.
What belongs in it
Only what the model cannot infer and must not get wrong. A bible is not a wiki. Every line you add is re-read on every single request, competing for room with the scene you actually want written.
The short list that earns its place: each character’s name, role, what they want and what holds them back; the places that recur, with the one or two details that make them recognisable; the rules of your world a reader would notice being broken; and what has already happened, in order.
What to leave out
Backstory nobody will reference. The grandfather’s war, the full history of the kingdom, the seventh edge case of the magic system. If it has not come up on the page and will not come up in the next three chapters, it is costing you room and buying nothing.
Prose. Do not paste finished scenes into the bible. The model does not need your text in order to stay consistent; it needs your facts. A bible full of prose is a bible that stops fitting.
How to write the entries
Short, flat, factual. "Mara, 34, field medic. Wants her licence back. Will not ask anyone for help." That is a usable entry. A paragraph of characterisation is not — it reads beautifully and gives the model nothing to check itself against.
Write the bonds as directions, not pairs. "Mara resents Teo" and "Teo admires Mara" are two different facts, and the second is the one that generates scenes. "Mara and Teo have a complicated relationship" generates nothing at all.
Why it drifts anyway
Because the bible is a message, and messages scroll out. What the model can read in one go is large but finite; once the thread outgrows it, the oldest messages stop being sent — including your bible, if you pasted it early. That is why the advice is to re-paste it, and re-pasting is the part everybody eventually stops doing.
And because nothing updates it. Every scene you write creates new facts: a wound, a promise, a door that is now locked. The document only knows them if you go back and type them in. By chapter fifteen it describes a book you are no longer writing.
When to stop keeping one by hand
A hand-kept bible is the right tool for a short project — a novella, a fanfic of a few chapters, anything you will finish in weeks. The upkeep stays small because the story stays small, and you should not buy a tool to replace a text file.
It stops being the right tool when the upkeep becomes a second job, and the question changes. It is no longer how to write a better bible. It is whether your cast and your places should be records written by the specialist that created them — a role, a want, a thing that holds them back — with each scene carrying a brief saying what it has to do to the reader, so the only thing you ever type is the story.
Common questions
How long should a story bible be?
Short enough that you will actually keep it current, which in practice means about one line per character and one per recurring place. Length is not the real constraint, upkeep is: a four-page bible three chapters out of date is worse than a one-page bible that is accurate, because you will trust it.
Do I have to paste it in every message?
Paste it whenever details start coming back wrong, and at the start of any long session. There is no way to make it stick. A chat re-reads the thread on every turn, so anything that has scrolled out of the window is simply not there any more, however carefully you wrote it.