So if you haven't notice by my posts I'm an avid lover of converting things... in this case game settings that can be used to populate the Milky Way.

Worlds

RIFTs by Palladium Games ; the Coalition in many respects mirrors the Imperium of Man - perhaps the Coalition is a remnant of a bygone age on some backwater world - now - unable to leave that world the Creed has been molded into something different...

A.R.C.H.I.E. - sounds like either a faction of the Mechanics that went awol or or perhaps a faction of the Coalition who defeated the Mechanicus long ago and thusly has evolved into what it is today... Perhaps a new A.I. has arisen either which way possibilities here are many and varied.

The actual Rifts themselves - sound like Warp Gates - perhaps the things that come into our material realm can't leave this world - thus whats found here is localized and not found elsewhere in 40k

Mutant Chronicles ; this is something I'm toying with right now - just replace the names of the Corps and Institutions - and at the end of the day who can deny that Mutant Chronicles is a watered down 40k clone...

I placed the whole campaign in its own "lost" sector - thus I can use the Earth SOLAR SYSTEM backdrop they describe albiet with a few name changes...

Algeroth and Ilian and such; sound like Chaos Champions or Daemon Lords from 40k - SUFFICE TO SAY not Space Marines who've turned - but rather humans who were transformed - at least that's how I'd covert them - if actual things from the warp never born aka Daemons then no further explanation is necessary LOL

Paranoia ; even this old RPG can be giving a place among the stars that make up the Imperium of Man...

Depending on what you want to do - if visiting such a location - then the PCs can learn by window dressing how an A.I. can go wrong - on the other end of the spectrum - maybe the players are captured - this game would be good for that type of scenario too - otherwise this RPG can serve as a good setting for a blatantly awry world...

Cyberpunk / Shadowrun ; depending on your bent - these setting would serve as a wonderful backdrop to a Luxury World and or a Lost World - whereby technology is "being" understood - i.e. people are or have been learning that technology is tech and not spiritual in nature - such a world would provide any visiting PC with the opportunity to gain unseen and unknown cybernetics - if going for more of a Shadowrun feel - replace "mana" aka magic with all forms of Psychic phenomenon - in SR there is an event known as the Awakening - maybe here that event unlocked psychic potential in much of the population!

EXAMPLE: SR - Shadowtech BOOK - Page 89 "Compounds" would work perfectly for Biologis types! (just saying)

Dune ; a limited run RPG that's hard to find - in my what has been deemed on this forum as Morbidverse (lol) can be found in the Andromeda Galaxy - long ago when the first people went out to their foothold during the old night maybe a ship got lost and ended up in the next nearest Galaxy - from that one ship - enough breeding stock would in time give rise to an Empire like that found in Dune... For me I'd use this as a one off adventure in my campaign or perhaps as a strange encounter - offering up something familiar and close to the heart for some who love Dune but not overshadowing the 40k experience.

What Game Systems have you used to populate your Campaign?

Stay GAMING

Morbid

Eclipse Phase: the setting is just mysterious enough to be an actual part of 40k: it effectively has the Warp (powerful exurgent effects) and the Chaos Gods (TITANS) already! They've had a war with Iron Men, and seem to be having the same technoprogressivism debates the AdMech has had in the past. Exurgent "infections" (ie, chaos cults and psykers) are becoming more frequent...

I'd fluff it as a system settled during the Dark Age of technology by fanatics who fashioned the planets to resemble those of the Solar system, and then the lie became truth as aeons passed and everything was forgotten. Maybe the proof could be on "Earth"...

It's not exactly an RPG setting, but a lot of my campaign takes place in sector Koprulu. Local humans used low-grade warp drive in M3, so they believe it's M3, but we know what it really is.

Imperium tried to take control on sector earlier with Admiral DuGalle expedition, but Admiral failed, not without xeno treachery. So now it's kind of Expance - there is voices that Imperium should capture the sector for good, but it can't now there is some more pressing issues. So it's a place where agents and RT working, with low-level colonization and prepairing to avenge DuGalle and punish locals for xenophilia.

There is no big warp incursions there, and there is a reason - Khaydarin crystal system across the sector and kinda of daemon prisons all around. But now, with Amon fall, destruction of Xel'Naga (Old Ones) legacy and releasing the daemons situation is gonna change.

The television series "Serenity" and "Kill Joys" could be salvaged and milked for ideas.

The RPG "Alpha Omega" has a blend of high-tech and superatural powers (plus demons) that makes it an easy salvage, too. I once got myself their creature book "the Encountered" simply for that reason.

I forgot the RPG Fading Suns !

Maybe this could be either a lost sector or perhaps as a variant "future" for the Dune empire I mentioned earlier in this post or simply use this setting instead of the Dune one in total...

For those who don't know - the gist of this setting is - the Stars are dying out - seemingly like the end of all things!

Robotech - perhaps the SDF1 never makes it back to earth or such a vessel could be developed elsewhere - even outside out galaxy (i.e. during the Old Night)...

I personally wouldn't use Zentradi ( too human for my tastes - I prefer aliens to be well more alien in their construction ) - rather I'd opt to use the Invid exclusively in this mashup timeline - with the "people" of Robotech fighting the Invid - I would place this "setting" far away from mainstream 40k territory - i.e. maybe a lost sector cut off by warp storms or for the more bold maybe these people left the galaxy during pre-Imperial history?

Judge Dredd ; there is a d20 variant RPG of this setting I believe...

What you got - Judges look and sound a lot like Arbites, then there are Psykers in the setting and of course mutants, robots, and cyborgs...

Scorched Earth aka the setting had its Megacities (i.e. Hives) and a desiccated landscape in and in between.

Maybe such a world is under the rule of a "backwards" force of Arbites?

I've primarily converted stuff from Ravenloft and Warhammer Fantasy Roleplay 2nd Edition to my games.

Ravenloft has tons of creepy monsters that can be adapted with some creativity, and used to fill the roles of xenos and warp creatures. One of my faves that I've adapted is the Skin Thief, an eight-claw fingered ursine creature which can tear off a person's skin in a single round and then wear it to impersonate them. I've also ported a version of the Vistani to my games as well (admittedly to Rogue Trader rather than DH2), and draw off of their culture and powers to make interesting and fleshed out void gypsies.

Of course, Warhammer Fantasy Roleplay 2nd edition is kind of a lazy port, as it is still just another version of the same themes found in 40K, and follows the earliest iteration of the rules that all the present 40K games use, but then, that's also what makes it such a good source book for surprising things that just fit easily into the setting and rules with very little effort. I've had many a Warp Sorcerer channel magic spells straight out of fantasy at my players, because the Warp does not follow the rigid rules of Imperial disciplines. The first time I had a warp creature cast 'Life Drain' on one of my players, he nearly **** himself.

Because the FFG 40K ruleset is broad and Mutable, it could be used within pretty much any setting. I have been toying with running some old 3e Forgotten Realms DnD modules using a set of low tech characters, derived either from DH or RT. A slightly more daring project, that will take a bit more work in setting up and balancing would be to overlay DH rules on a World of Darkness setting... but I'd have to do a hell of a lot of playing around with mutations, Nav powers and Psy disciplines to get it to work... some day, when work is not such a drag and my kids are grown

I did a D&D-esk camapign for DH - all the PCs were native born Fuedal / Feral Worlders...

The premised being; said planet was the last planet by which "man" has been preordained to fight his final battle - and as such - the final battlefield must be staged in order to allow for a fair fight (in Gist of course)...

Translation: keep the world secret and safe, eliminate any threats that could cause ruin when the Imperium arrives enmass at the end of M41
ATM the Imperium nor the powers that be knew of this world nor its intended future

I had the PCs choose primitive gear and the like - with an opportunity to collect M41 gear from a crashed Voidship lost in a mountain range

I posted the whole idea of it all in this website - Morbid

Doom 2016

Sort of reminds me of a warp scorched world...

For Dark Heresy, I think the only other RPG line that I've borrowed from has been Gamma World. Anything I take from D&D or Iron Kingdoms ends up in my WFRP campaign instead. I have drawn DH inspiration from a few miniatures games (including Dark Age and Kingdom Death) and of course movies (including Fury Road and Frankenstein's Army).

But I think one of my biggest sources of inspiration actually comes from a simple source which people sometimes overlook: art . Search the word "disturbing" on DeviantArt some time; you'll find tons of nightmare fuel.