Warhammer 40,000 has always had canon. It’s just a canon built on ten thousand years of corrupted records and institutional failure. The Imperium is a civilization that records history through layers of propaganda, theological revision, and bureaucratic incompetence. Its official records contradict themselves constantly. One book describes an Astartes fighting on after losing half his torso while another kills him with a single chest wound. Both are ‘true’ because the Imperium lost the ability to verify anything ten thousand years ago. What’s gospel on one world is heresy on another. The universe holds together through contradiction and the threat of violence for questioning it.
Games Workshop has spent decades turning that decay into structure. The setting isn’t designed for factual cohesion but for the atmosphere of a civilization collapsing under its own weight. It’s meant to be unreliable. The lies, mistranslations, and half-remembered legends of the Imperium filter into how the fiction works. When fans argue over the origins of a Chapter or the mechanics of warp travel, that confusion is intentional. The contradictions reinforce the idea that this is an empire where no one has the full picture because the full picture was destroyed during the Heresy and whatever survived has been rewritten by fanatics for ten millennia.

That’s what makes the setting function. Warhammer’s “canon” is flexible inside its own collapse. It keeps a stable foundation—who the Emperor is, what the Imperium worships—but everything else is conditional, filtered through institutional memory loss and deliberate mythmaking. It’s a system that survives on interpretation because interpretation is all that remains.
Amazon’s TV series threatens to destroy that. Television cannot survive on ambiguity. It needs a single, clear version of events that holds across episodes and seasons. A script cannot rely on lore contradictions for texture—it has to pick one interpretation and cement it. The moment that happens, the illusion of unreliable history collapses. Once something has been filmed, it becomes the definitive version of that event for millions of viewers. Astartes will have a fixed level of durability, the Heresy will have an official timeline, the Imperium’s theology will have visual shorthand. What used to exist as rumour becomes canonized fact.
That shift will spread back through Games Workshop’s entire operation. Once Amazon defines a look, a tone, or a narrative baseline, the rest of the franchise will align with it. Tabletop art, codex writing, and novels will drift toward that fixed image because mainstream audiences will not tolerate contradiction. The flexibility that allowed multiple conflicting “truths” will be replaced by brand coherence. The Imperium will stop being a decaying archive of contradictory records and start being a franchise with a unified vision.

Games Workshop has not been avoiding canon, they have been managing plausible unreliability. That’s what allows them to retcon without breaking continuity. They can rewrite the history of a world or change the founding story of a Space Marine Chapter because the Imperium’s history is already fractured beyond recovery. Amazon’s adaptation removes that protection. Once the story exists in visual continuity, it stops being propaganda and becomes scripture. The audience will see one version, and that version will override forty years of flexible interpretation.
The setting was built to avoid this exact problem. The Imperium’s institutional decay was a narrative tool that kept the lore functional. No single version ever dominated. Every author, codex, and game could contradict the last and still feel authentic because confusion was structural to the setting. Once the TV adaptation establishes a singular version of events, that design collapses. The setting stops functioning like the Imperium and starts functioning like every other corporate property with a lore bible and a merchandise strategy.
Warhammer’s survival has always depended on its unreliable narrator. The sense that even official sources are compromised, because they’re produced by a dying empire that has lost the ability to distinguish truth from necessity. That’s what makes the universe feel ancient and unfathomable. A television show cannot maintain that. It will have to pick sides, clarify motives, and define who’s right.
And once it does, Warhammer will lose the one thing that kept it alive for forty years: the freedom to contradict itself and still feel true.