Похоже, существуют два канона.

«With Warhammer and Warhammer 40,000, the notion of canon is a fallacy. [...] Warhammer and Warhammer 40,000 exist as tens of thousands of overlapping realities in the imaginations of games developers, writers, readers and gamers. None of those interpretations is wrong.»

Gav Thorpe, Lead Designer GW

«It all stems from the assumption that there's a binding contract between author and reader to adhere to some nonexistent subjective construct or 'true' representation of the setting. There is no such contract, and no such objective truth.»

Andy Hoare, Game Designer GW (in the comments)

«These are future histories. It's all already happened, but the reports we get from that far-flung era are unreliable, corrupted by distance and time and a billion unreliable narrators who know a fraction of what the rulebooks tell us.

Games Workshop actively encourages that attitude — the idea of everyone coming to 40K and seeing something slightly different: the same thing from a different angle. An author can say Character X was on World Y in Year Z, and another author might contradict it in something else written several years later if he or she has a different idea. Choose which you prefer? Assume both are false sightings and Character X was nowhere near either world? It's your call. That's the point. There is no canon. There are several hundred creators all adding to the melting pot of the IP.»

Aaron Dembski-Bowden, co-author Horus Heresy series

«Here's our standard line: Yes it's all official, but remember that we're reporting back from a time where stories aren't always true, or at least 100% accurate. If it has the 40K logo on it, it exists in the 40K universe. Or it was a legend that may well have happened. Or a rumour that may or may not have any truth behind it.»

Marc Gascogne, chief editor Black Library