What is canon in fiction?

In fiction, canon is the set of facts a story has established as true inside itself. The king is dead. Kai cannot use fire magic. The ship left on the fourth of March. The word traces back to the Greek kanon, a rule or measure, and it carries exactly that sense: canon is the standard against which everything else in the story is judged.

The concept matters most in long work. A short story can hold all of its own facts. A novel, a series, or a serial running hundreds of chapters cannot, and once a story is long enough, "what is true" stops being a memory and becomes a record.

What counts as canon

More things than you might think:

• Facts: events that happened, and when.
• States: who is injured, where they are, what they carry.
• Rules: what the world allows. Magic systems, technology, physics.
• Relationships: who trusts whom, and since when.
• Knowledge: which characters know which secrets.
• History: the backstory the text has committed to.

That last item, knowledge, is the one writers most often forget. A reveal only lands if nobody in the room could have known it earlier; that makes "who knew what, when" part of your canon.

A working model: six states for a fact

Not every piece of story information deserves the same confidence, and treating it all the same is how bibles get noisy. A useful practice is to track a state alongside each fact:

1. Established: the text explicitly says so.
2. Proposed: something you or a tool noticed and have not approved yet.
3. Inferred: strongly implied by what is written, but not stated.
4. Theory: a possible interpretation you are keeping in mind.
5. Unknown: the story has not said, and that is fine.
6. Rejected: was proposed, and you said no. Keep these so they do not come back.

The important rule: nothing moves from unknown, inferred or theory into established without a deliberate decision. Otherwise the record silently fills with things the story never actually said.

Canon drift

Later chapters contradict earlier ones for two very different reasons.

Accidental drift is the continuity error: the sword that returns after it shattered, the character in two cities on one day. It reads as a mistake because it is one. (See our guide to continuity errors.)

Deliberate change is the retcon: retroactive continuity, "a literary device in fiction whereby facts and events" the story established are later "adjusted, ignored, supplemented, or contradicted," as Wikipedia defines it. Retcons classically take three forms: addition (new backstory that does not contradict), alteration (new facts that contradict, such as resurrecting a dead character) and subtraction (quietly ignoring a story that happened). The defining trait is that a retcon is done deliberately, which is what separates it from a plot hole.

Hard rules and soft conventions

Not everything in canon has the same weight. Some conventions are treated by their readers as near-inviolable rules: the romance genre's expectation of a happy or satisfying ending is the classic example, policed hard by its community. Others are strong tendencies: grimdark's dour tone is an expectation, not a law. When you record a convention in your bible, note which kind it is, because breaking a hard rule reads as a broken promise while breaking a soft one may just be your take.

Managing canon while writing

• Keep one source of truth. If the truth lives in a notebook, a wiki and your memory, it lives nowhere.
• Date your facts and keep the history, so "what was true in chapter ten" stays answerable.
• Record where each fact was established, so you can always check the passage.
• When you deliberately break canon, write the decision down: what changed, why, and how far it reaches. A changelog of canon decisions is the cheapest insurance a long series can buy.

How Kanonara approaches this

Canon is the unit of work in Kanonara. When a chapter is analyzed, new facts come back as proposals with their evidence, and each waits for your accept or reject. What you accept becomes canon; what you reject is remembered as rejected. Apparent contradictions surface as Story Doctor alerts, and you can mark any of them intentional, which keeps deliberate strangeness from being flagged forever. See how Kanonara works.