Innovations

How the Fablyos engine keeps a story the same story.

A long interactive story is only as good as its memory. These papers describe the engineering behind that memory: how Fablyos checks what its own models record, and how it decides what to remember when it can't show the writer everything.

White paper · Revision 1

Verified Bookkeeping in the Fablyos Story Engine

Beat evidence, ledger supersession and slip-learned fact selection for long-form interactive fiction

Fablyos uses inexpensive models, and a cheap bookkeeper is often wrong. This paper describes two mechanisms that keep its errors from compounding. A plot beat counts only when the story itself can be quoted showing it. The facts ledger is a rebuildable view of the story, with provenance on every line, write-time retirement of contradicted facts, and fact selection that learns from the continuity slips it catches.

Kevin Lackey · 3 November 2026

Questions or corrections: Kevin@fablyos.com.