Why only the Milky Way?

[Blindhamster]

the milky way is actually incredibly large, far larger than you're ever likely to actually need for storytelling anyway.

Another game that uses the milky way is elite dangerous, i don't know if anyone here has played it and zoomed the map out, but it's literally mind blowing to view like that.

Why go beyond it other than "just because"

[Snazzy]

Maybe they have their own Men of Iron uprising, and those Men of Iron eventually start making their way back to the Milky Way. Lol anything is possible.

 

The Men of Iron never left.  They just lost.

[Rik Lightstar]

I just don't see that another galaxy would add anything.

 

The scale is already immense, far bigger than any of us as humans can really comprehend, there's "space" in the setting for pretty much any permutation of planet you could want to add.

 

Additional Xenos races could be added as there are areas of the Milky Way that remain largely unexplored by the Imperium.

 

Likewise lost civilisations of Humanity could exist in a single system or small sector.

 

TLDR: Yeah you could add "more space" but why?

 

Rik

[Urauloth]

It’s worth pointing out Ultramar is farther from Caliban than from The edge of the galaxy to the closest galaxy.

 

Yeah, it's easy to forget how big the galaxy is, especially when you look at the codex maps with just a couple of strategic highlights picked out. There are sections of it - even inside the reach of the astronomicon and within the nominal "borders" of the Imperium - which have been forgotten.

[Hrvat]

Indeed Imperium has "only" a million worlds in a galaxy of 100-400 billion stars and at least as many planets. So at the lowest estimate Imperium is in possession of 1/100 of a permille.  

[Azekai]

Indeed Imperium has "only" a million worlds in a galaxy of 100-400 billion stars and at least as many planets. So at the lowest estimate Imperium is in possession of 1/100 of a permille.

I sort of agree, in that 1 million worlds may actually be too few, however I think it is pretty clear that the ‘million worlds’ quote isn’t meant to be taken as literal gospel truth. ‘He is master of a million worlds’ sounds awesome but also very hand-waves. I wouldn’t take that to mean ‘the imperium has approximately 1 million planets under its jurisdiction’. There are two reasons for this; the first is that one of the big schticks of the setting is that the Administratum is terrifyingly out of touch. Whole sectors plunge into darkness and no one notices for hundreds of years. Getting an accurate read on this number of planets in the Imperium seems untenable, in universe.

 

The second is a meta-reason: a million planets is still more than enough room for everyone to make up stuff about their own little home-grown campaign. It isn’t 6 planets, or a hundred systems. It’s a million+ worlds, more than the Lexicanum (or you or I) could track.

[Elzender]

Maybe another factor is the kind of weapons from the Dark Age of Technology? I recall mentions of names such as Sun snuffers. If that kind of weaponry available to mankind, it was likely to combat threats at that scale. Thus, it could be feasible that entire portions of the galaxy were pretty much left barren when conflicts that required them happened. Still, it is quite likely that the "a million worlds" statement, even if given as a vague number, comes from a mix of two factors:

 

- First, a possible lack of knowledge, unless some of the original creators had some knowledge of astronomy or at least scientific background. Then again, that phrase is likely +30 years old now, so the amount of knowledge regarding the extent of the Milky Way has substantially changed, if not for the scientific community at least for the general population. I personally had no idea of its size, and then again the numbers given here are pretty much meaningless to me, as it is impossible for me to conceptualise the extent of it.

 

- Second, as others have remarked, is the scope of the setting. An Imperium actually spanning the majority of the Milky Way would probably be impossible to flesh out in a believable way, even for the standards of this setting. If we already have a bit of a "small world" syndrome with some characters in the current setting where we're told no individual has much chance of making an impact, expanding it to the real span would probably render pretty much all of them meaningless, as well as the whole game system.

[jaxom]

The Voyager probe is going approximately 35,000 miles per hour and it will be another 40,000 years before it's closer a star that isn't our sun.

 

The galaxy is huge. The space between galaxies is even larger. Sufficient hand waving can bridge the gap, but it also then requires the hand-waving of galactic-scale logistics.