I've been thinking about this since I first started playing Dark Heresy a couple of years back:

Alright, let's imagine that at the end of a Black Crusade campaign the Corpse-Emperor is destroyed and Terra gets absolutely sacked. The Imperium is defeated and humanity lies, once again, scattered across the stars while the xenos and the dark forces of the Warp ravage the galaxy.

Now then, what would the galaxy be like, and what would a campaign set in the post-Imperial galaxy be like, whether the players are heretics or not?

It would never happen.

The All-Father would return to lead Mankind to victory. Or Guiilaman's wounds would heal and he'd lead them to victory. Or the Khan...

In all honesty, it would be a boring setting. No hope for humanity, no cohesiveness for Chaos, everyone battling their tiny wars against multiple xenos races for no gains on either side. Ten thousand years undone is not remade or even resolved in the span of a "campaign." More importantly, think of everything you have to detail in such a setting. Think of everything you detail being either unacceptable to your players, or being taken for granted by your players. They know it's your game, you can detail all you want, but all they have to do is ignore the details. I caution you to heed my words: the experience will not live up to the expectation. And that will be a great disappointment.

Ah, you're probably right. It sounded a lot better in my head earlier. Not that I'd run a game like that, personally.

It all depends on what were the consequences of the Emperor being destroyed.....

Was there a powerful enough figure to lead the unified chaos armies in a realm rivalling the size of the old imperium. As the False Emperor was proven to be..... well false by his death would the old armies of the imperium flock to this new conqueror as the new true emperor of the Imperium. Sure there would be pockets of resistance of those who serve the old dead God and others who seek to rule for themselves in the name of the Chaos Gods but a unified Empire in service to Chaos would be a scary, scary thing and have huge implications for the other factions such as the Tau, Necrons and Orks (the Eldar might just crawl up into a foetal position and die at this point).

Never let established thinking ruin what could be a unique and entertaining idea even if it is an alternate universe type thing.

another thing to consider is what will HAPPEN if/when the god emperor dies. while the most likely effect is just he goes poof. there's been specualtion that because of the belife in him of humanity he will ascend to true godhood.

As BrianDavion says, we don't know what will happen if the emperor dies. I play a heretic who believes that the golden throne is effectively a prison and that, had the emperor been allowed to die, he would have reincarnated by now and we'd have a new golden age.

Needless to say, my character is plotting to kill the emperor out of loyalty to the emperor. Or so they believe.

The single greatest implication of the Emperor's death would be the death of the Astronomican.

No more (effective) warptravel for humankind, and many others.

Consider that for a while.

Agreed with Fgdsfg, the biggest issue is that there's no effective way for humans to travel between the stars anymore. Most planets will have it's population starve to death. The rest are picked off one by one. A waaagh happens? Good luck, you only have one planet worth of humans to stop it.

It sounds rather boring because humans effectively becomes unable to defend themselves against the horrors out there.

The single greatest implication of the Emperor's death would be the death of the Astronomican.

No more (effective) warptravel for humankind, and many others.

Consider that for a while.

You mean Imperials rather than humankind. There are other ways to guide a ship in the Warp (and Chaos ships are more seldom lost than Imperial ones...).

The most immediate consequence would be that travel beyond a sector or even a sub sector would be impossible (as in most ships would get lost) if you previously relied on a navigator.

The single greatest implication of the Emperor's death would be the death of the Astronomican.

No more (effective) warptravel for humankind, and many others.

Consider that for a while.

You mean Imperials rather than humankind. There are other ways to guide a ship in the Warp (and Chaos ships are more seldom lost than Imperial ones...).

The most immediate consequence would be that travel beyond a sector or even a sub sector would be impossible (as in most ships would get lost) if you previously relied on a navigator.

Even big badass chaos people do get lost or the travel doesn't go quite as expected, like Angron! How chaos navigate isn't fleshed out in any meaningful way compared to the imperials. Some are mentioned using fallen navigators I believe, others do short calculated jumps. Or pray to the gods and hope it goes well!

Now, only one of those are reliable, mainly the calculated jumps. But they're short, really really short. And the majority of imperial worlds aren't independantly viable societies. Hive worlds need food from off world, same with forgeworlds. Not to mention they need minerals to keep up production.

And it's not like they all convert to chaos instantly, nor that chaos is likely to be able to make functioning societies in the long run.

If the emperor dies his armies pretty much die with him and humanity looses to xeno in some way or another. I just don't see any other outcome.

You're assuming that the Chaos powers that won won't have their own way of allowing their human minions to travel through the warp. Since they already can it's not a big step that an Empire of the Ruinous Powers will find their own way to traverse the warp, even if it's by seating another powerful entity upon the Golden Throne (there are rumours this has already been done depending on what you read).

Also out of curiousity does anyone remember how the armies of the Great Crusade navigated the warp before the Emperor ascended the Golden Throne?

And BrianDavon raises a very good point, there are a lot of rumours the the Emperor is able to reincarnate and if he was removed from the Golden Throne that keeps him alive he would be able to rebirth to lead humanity into a new Golden Age, another exciting possibility to explore.

As I said before don't let bland conventional thinking throw you off what could be a very interesting idea.

Even big badass chaos people do get lost or the travel doesn't go quite as expected, like Angron! How chaos navigate isn't fleshed out in any meaningful way compared to the imperials. Some are mentioned using fallen navigators I believe, others do short calculated jumps. Or pray to the gods and hope it goes well!

Now, only one of those are reliable, mainly the calculated jumps. But they're short, really really short. And the majority of imperial worlds aren't independantly viable societies. Hive worlds need food from off world, same with forgeworlds. Not to mention they need minerals to keep up production.

And it's not like they all convert to chaos instantly, nor that chaos is likely to be able to make functioning societies in the long run.

If the emperor dies his armies pretty much die with him and humanity looses to xeno in some way or another. I just don't see any other outcome.

First of all, I dare say that chaotic ships travel in a safer way through the Warp. Some ships are lost, true, but most chaos fleets happen (mostly) exactly where they want when they want, or most Crusades wouldn't pose even a threat to the Imperium. Sorcerers, rituals, bound daemonhosts, the favour of the Gods, pick your choice... see the example of Octavia in the Night Lords trilogy (recommend the read). She (a navigator) learns pretty quickly how to manage without the light of the Astronomican. It's not fleshed out, but it's precisely the lack of occurences of chaotic ships getting lost in the fluff that makes me say they have reliable methods (if sometimes a bit more fickle...)

As for the survival of humankind: space is vast. Finding an inhabited system, or even a sub-sector, or even a sector, at random is very unlikely. So no, humanity wouldn't be wiped out, it would only be stranded, and while many worlds would be destroyed, thousands more would still exist peacefully in space, ignored by xenos species that have either no interest in or no way of happening upon the world. Humanity survived the Age of Strife, it can endure some more I think.

Also out of curiousity does anyone remember how the armies of the Great Crusade navigated the warp before the Emperor ascended the Golden Throne?

The Astronomican is one of the first major institutions founded by the Emperor after the Unification of Terra. My guess is that as long as he was alive and in full control of his abilities, channeling the energies of psykers bound to him to create a psychic beacon only took a fraction of his attention, no matter how far he was. Plus the Warp was extremely calm during the Great Crusade, up until the Heresy.

You mean Imperials rather than humankind. There are other ways to guide a ship in the Warp (and Chaos ships are more seldom lost than Imperial ones...).

It's not obfuscated in any way. Anyone can use it, human or non-human, as long as they have a meaningful psychic potential or can act as a Navigator.

There *are* other ways to traverse the Warp, yes, but part of my point was "effective" warp-travel. No other way than what the Imperials use can really be described as "effective". It's small, calculated jumps into uncertain and dangerous areas, with few or no points of reference once you're attempting the jump.

Do you really think that just because some humans go corrupt, they'll suddenly change and revise the entire way they perform space-travel, when there's a nice superbeacon still shining, like, right there ?

Chaotic ships in no way use the Astronomican, and yet they still manage impressive jumps, even going in and out of the Eye of Terror, which is probably the most dangerous zone of "realspace" (if such a term can be applied to it), and in which the light of the Astronomican certainly doesn't shine. It's perfectly doable. Example: a Word Bearers armada jumping from the Eye directly to Ultramar, unnoticed before they arrive. Honsou does the same. The Eye and Ultramar are at opposite points of the galaxy.

I remember a short story about an Imperial ship being followed in the Warp by a chaotic ship, to which the ship's captain remarks it's theoretically impossible. Imperials, deprived of the Astronomican, would be lost, yes. Heretics have since long developped methods that simply do not require it at all. You can have your interpretation of the fluff, sure, but most of the written material makes me pretty sure that what I say is "canon".

And remember: we're not talking about rational people here. I don't picture most Heretics willingly guiding themselves with the Corpse-Emperor's nightstand lamp.

K0balt, where does it say they don't use the Astronomican? I've seen some references where it says they go with the tides of the warp, but nothing spesifically against using it or navigators.

I think heretics would love the idea, they love corrupting everything else for their purpose so why not?

Also, what about, you know, the rest of humanity? which isn't chaos but relies on the astronomicon. I guess they're doomed then?

K0balt, where does it say they don't use the Astronomican? I've seen some references where it says they go with the tides of the warp, but nothing spesifically against using it or navigators.

I think heretics would love the idea, they love corrupting everything else for their purpose so why not?

Also, what about, you know, the rest of humanity? which isn't chaos but relies on the astronomicon. I guess they're doomed then?

First question:

I think a Heretic would find the very idea disgusting. And rarely do I see a mention in fluff of Chaos navigation and Astronomican. I mean, cultists creating psychic beacons through sacrifices to invite chaos invasions? mentionned. Fallen navigators learning to feel the Warp rather than simply interpret its currents? mentionned. Sorcerers, bound daemonhosts, weird abaci, rituals? mentionned. Good-old navigators relying on the Astronomican to guide a chaotic ship? I'm sorry, but no example comes to mind. I don't say they don't exist. I'm saying that other heretical methods of navigating the warp exist, and they tend to have the favour of, well, Heretics.

Second question:

as directly quoted from my previous post:

"Imperials, deprived of the Astronomican, would be lost, yes." As lost as someone in a storm, on an ocean, without compass, map or any kind of navigation tool.

They're doomed to remain stuck in their own sector/sub-sector. At least until they resort to more heretical methods.

Where is it mentioned? I've tried looking at the wiki and lexicanum, I even looked through my CSM codex and didn't find much.

Chaotic ships in no way use the Astronomican, [...]

[...] and yet they still manage impressive jumps, even going in and out of the Eye of Terror, which is probably the most dangerous zone of "realspace" (if such a term can be applied to it), and in which the light of the Astronomican certainly doesn't shine. It's perfectly doable. Example: a Word Bearers armada jumping from the Eye directly to Ultramar, unnoticed before they arrive. Honsou does the same. The Eye and Ultramar are at opposite points of the galaxy.

The Astronomican is centered on Terra, shining to the edges of the galaxy. The Astronomican definitely shines throughout the Eye of Terror. The Eye of Terror is just a rift between realspace and The Immaterium, and as far as I know, there's absolutely no reason the Eye of Terror would somehow block the Light of the Astronomican.

I remember a short story about an Imperial ship being followed in the Warp by a chaotic ship, to which the ship's captain remarks it's theoretically impossible. Imperials, deprived of the Astronomican, would be lost, yes. Heretics have since long developped methods that simply do not require it at all. You can have your interpretation of the fluff, sure, but most of the written material makes me pretty sure that what I say is "canon".

If you know of the way the forces of Chaos navigates in general, you've got me bested. By all means, explain how they do it, or cite a source.

And remember: we're not talking about rational people here. I don't picture most Heretics willingly guiding themselves with the Corpse-Emperor's nightstand lamp.

And why wouldn't they? Pride? The Astronomican is hardly a "nightstand lamp" - it's an enormous psychic beacon that is at a fixed location in both the Materium and the Immaterium - something that, as far as I know, doesn't otherwise exist.

While I do not contend that there are other ways to navigate the warp, because there certainly are several ways, all which are incredibly taxing or otherwise inefficient, to say that the forces of chaos have "since long developped methods" to navigate the Warp is unfounded hogwash.

The more powerful servants of Chaos (CSM, Daemon Princes, etc) surely stick to techno-arcane sorcery and the favours of their dark masters, of this I am sure and fully agree with you on. But not only is only a comparative minuscule amount of humanity truly dedicated to the dark gods, but even the vast majority of those, the Lost and the Damned, would not be directly favoured by their black patrons, nor have access to means of travel aside from what they had when they left the Imperium, but more importantly; they have no cause to abandon this form of transportation for as long as the Astronomican remains, nor direct access to the resources needed to make the transition(s) needed once it's not.

Where is it mentioned? I've tried looking at the wiki and lexicanum, I even looked through my CSM codex and didn't find much.

Which one? The lexicanum and wiki both are severely lacking, and I don't imagine the csm codex mentioning much about navigation.

Chaotic ships in no way use the Astronomican, [...]

[citation needed]

[...] and yet they still manage impressive jumps, even going in and out of the Eye of Terror, which is probably the most dangerous zone of "realspace" (if such a term can be applied to it), and in which the light of the Astronomican certainly doesn't shine. It's perfectly doable. Example: a Word Bearers armada jumping from the Eye directly to Ultramar, unnoticed before they arrive. Honsou does the same. The Eye and Ultramar are at opposite points of the galaxy.

The Astronomican is centered on Terra, shining to the edges of the galaxy. The Astronomican definitely shines throughout the Eye of Terror. The Eye of Terror is just a rift between realspace and The Immaterium, and as far as I know, there's absolutely no reason the Eye of Terror would somehow block the Light of the Astronomican.

I remember a short story about an Imperial ship being followed in the Warp by a chaotic ship, to which the ship's captain remarks it's theoretically impossible. Imperials, deprived of the Astronomican, would be lost, yes. Heretics have since long developped methods that simply do not require it at all. You can have your interpretation of the fluff, sure, but most of the written material makes me pretty sure that what I say is "canon".

If you know of the way the forces of Chaos navigates in general, you've got me bested. By all means, explain how they do it, or cite a source.

And remember: we're not talking about rational people here. I don't picture most Heretics willingly guiding themselves with the Corpse-Emperor's nightstand lamp.

And why wouldn't they? Pride? The Astronomican is hardly a "nightstand lamp" - it's an enormous psychic beacon that is at a fixed location in both the Materium and the Immaterium - something that, as far as I know, doesn't otherwise exist.

While I do not contend that there are other ways to navigate the warp, because there certainly are several ways, all which are incredibly taxing or otherwise inefficient, to say that the forces of chaos have "since long developped methods" to navigate the Warp is unfounded hogwash.

The more powerful servants of Chaos (CSM, Daemon Princes, etc) surely stick to techno-arcane sorcery and the favours of their dark masters, of this I am sure and fully agree with you on. But not only is only a comparative minuscule amount of humanity truly dedicated to the dark gods, but even the vast majority of those, the Lost and the Damned, would not be directly favoured by their black patrons, nor have access to means of travel aside from what they had when they left the Imperium, but more importantly; they have no cause to abandon this form of transportation for as long as the Astronomican remains, nor direct access to the resources needed to make the transition(s) needed once it's not.

In order:

-I have no citation for that, true. What I do have is a number of examples of my thesis, and none of Heretics using the Astronomican. Not to say that doesn't happen (I went a bit overboard on that one, granted), but given the sparse nature of evidence when it comes to 40k fluff, I call that (circumstantial if you wish) evidence.

-It does, as seen in the novel Angel Exterminatus. The fleets of Perturabo and Fulgrim have to be guided in by Dark Eldar.

-What I have are examples. Octavia and Ruven in the Night Lords trilogy (one cannot see the beacon and relies on sorcerous powers, the other is a Navigator but learns to do without it); the Word Bearers fleet in the Word Bearers trilogy (navigators are mentionned, but again, the light of the Astronomican is conspicuously absent from any description); Honsou attacks Ultramar and appears suddenly in system within range of the orbital defenses (which no navigator can do, at least not that purposefully); in Execution Hour, a daemonhost guides a ship more easily and accurately than a navigator would; Typhus guiding the Death Guard to Nurgle's loving bosom; etc.. I have other examples of this, but this is already plenty.

-Pride? No. Hatred? **** yes. Hatred is the most powerful motivator known to man, and I'm not even considering Heretics here, just regular human beings.

10000 years is plenty enough to be considered "since long". Unfounded hogwash? See above. And they seem more precise to me, since Chaos fleets seem to have way more accuracy in where they strike compared to the numerous accounts of lost Imperial fleets...

And those Lost and Damned you mention own their own ships? And move on their own, unbidden by other masters? Then they are pretty powerful already, and the Captain of such a ship could certainly curry favour with the Dark Gods. The heretics that stay in realspace and don't hide where the Astronomican don't shine (namely the Eye, Vortex, Maelstrom or some such) generally don't last long; conversely, going into a previously mentioned warpstorm with just a navigator is considered suicide (by the navigators themselves, see p. 327 of the Black Crusade Core Rulebook, in the first paragraphs).

So either the Heretics have another, reliable way of navigating the Vortex or... or nothing. They just die or get lost.

Most of the Lost and Damned that you describe are either the troops of those powerful Champions, and generally have little say in their fate, or live on chaotic planets and rarely take ships to go anywhere.

The only heretics that I would see (grudgingly) use the Astronomican are those that try to pass for Imperials.

Edited for clarity, grammar, spelling, and citations.

An interesting debate that relies heavily on examples for both sides.

Remember though how you want it to be is how it is in your particular games, there is no right or wrong and you are only bound by your imaginations and how you perceive it should be personally.

Any problem or shortfall can be overcome with enough creativity and forthought.

That's my last take on it I'll now let the debate continue ;-).

Personally, I do not see the death of the Astronomican posing more than a temporary nuisance for the forces of Chaos. Even if they would use it to navigate the Empyrean (which is possible, seeing as it essentially acts as their goal line, a huge psychic light calling "this way to Terra!"), we have to keep in mind that the Astronomican's effect may well be replicated. To me, psychic powers are not unique, and if said beacon acts like "a light in the Warp" that is strong enough to be seen from anywhere through the Warp, then this sounds suspiciously close to the light-like presence that any potentially psychic species has, with actual psykers shining much brighter. In theory, I could well imagine a powerful Daemon Prince or perhaps a Daemon Primarch replacing the Astronomican with his own corrupted presence.

As for a post-Imperial galaxy, contrary to most I think it could make for an interesting background. We simply have to accept that it would be a very unfamiliar one, which I think is both frightening as well as potentially exciting. For an example from another sci-fi setting, the new "Legacy" era of Star Wars features a very different setting that is still heavily influenced by what one may know from the movies or older books, but at the same time feels refreshingly new in that it features entirely new factions, or had existing factions evolve into something that one may have never expected .

I would predict that Chaos would play a much more important role in such a setting, however, and that it would be a very different game. I do not believe that a "Chaos Imperium" would exist for long without splintering into countless factions all at odds with each other. Chaos is inherently self-destructive in that it encourages strife rather than cooperation. The only way to bring multiple followers of Chaos together would be either by brutal force or by pointing everyone at a common enemy. With the Emperor's death, the latter would be gone, and the former would be impossible due to the sheer size of the current IoM. The result would be countless local warlords all with their own armies and strongholds and allegiances and alliances. And the best thing: This is just like their gods would want it.

So, I think campaigns in such a setting could be like a mixture of Black Crusade and Rogue Trader, where the players attempt to impress their NPC lord and master by fighting his or her enemies, all the while plotting a coup to someday take over. Alternatively, it could be like a twisted version of Dark Heresy where players are bounty hunters eradicating the last remnants of the forbidden cult of the dead Emperor; common people who grew up in a Chaos-dominated society but who were picked by an influential Chaos lord for their skills and talents.

And then of course there could be campaigns where the players instead play as members of a local resistance, be it humans or aliens, or even an alliance that, in the face of Chaos as everyone's enemy, transcends the xenophobic racism that has dominated interspecies relationships for millennia...

The potential is there. All you need is to do is figure out how to use it.

The end of Astronomican won't be fatal for the Imperium. Check Rogue Trader Navis Primer: it seriously helps, boosting success by 20%, but having a stable route and maps you'll get to your destination just fine (no warp storms, though).

Death of the Emperor will open the Webway entrance/exit (Golden Throne), full of demons, so Terra is pretty much gone with Administratum. Mars will follow shortly after. Will there be a new Eye of Terror and new Chaos God? That would be cool.

Warning! SPOILERS MAY FOLLOW!

In Night Lords novels the vision is that humans will ask Eldars for help, but that should be taken care of by union of Night Lords warbands.

In Horus Heresy: Legion novel Cabal foresees that Horus, winning the battle, will turn against other marines later and in 2 generations humanity will be gone. That didn't happen, so Alpha Legion actions will, most probably, turn the tide of the last battles in favor of either chaos (Abbadon's Black Crusade) or remaining loyalists.

It's said that if Emperor "wins", the stagnation of Imperium of Man will last about 10-20 millenias. Considering that in the last W40K tabletop wargame it's written that AdMech have found unrepairable damage in Golden Throne, I wonder if Games Workshop will have balls to continue the story during our lifetime.

If all that happens, most of humanity will die and remaining planets will be like Q'Sal or agriworlds.

Chaotic ships in no way use the Astronomican, [...]

[citation needed]

I remember a short story about an Imperial ship being followed in the Warp by a chaotic ship, to which the ship's captain remarks it's theoretically impossible. Imperials, deprived of the Astronomican, would be lost, yes. Heretics have since long developped methods that simply do not require it at all. You can have your interpretation of the fluff, sure, but most of the written material makes me pretty sure that what I say is "canon".

If you know of the way the forces of Chaos navigates in general, you've got me bested. By all means, explain how they do it, or cite a source.

And remember: we're not talking about rational people here. I don't picture most Heretics willingly guiding themselves with the Corpse-Emperor's nightstand lamp.

And why wouldn't they? Pride? The Astronomican is hardly a "nightstand lamp" - it's an enormous psychic beacon that is at a fixed location in both the Materium and the Immaterium - something that, as far as I know, doesn't otherwise exist.

While I do not contend that there are other ways to navigate the warp, because there certainly are several ways, all which are incredibly taxing or otherwise inefficient, to say that the forces of chaos have "since long developped methods" to navigate the Warp is unfounded hogwash.

The more powerful servants of Chaos (CSM, Daemon Princes, etc) surely stick to techno-arcane sorcery and the favours of their dark masters, of this I am sure and fully agree with you on. But not only is only a comparative minuscule amount of humanity truly dedicated to the dark gods, but even the vast majority of those, the Lost and the Damned, would not be directly favoured by their black patrons, nor have access to means of travel aside from what they had when they left the Imperium, but more importantly; they have no cause to abandon this form of transportation for as long as the Astronomican remains, nor direct access to the resources needed to make the transition(s) needed once it's not.

The FIrst Claw series mentions using the 'dark shadows' in the warp rather than the Astronomicons light, and that navigators had to be trained how to do it, using riskier currents and routes. Whether this was just them, or a Night Lords thing in general, or a wide spread Legion ability, is not made clear.

Black Crusade explicitly states (somewhere) that Chaos vessels, at least in area like the Eye of Terror, use other means that the Astronomicon.

[...]

If all that happens, most of humanity will die and remaining planets will be like Q'Sal or agriworlds.

I was always under the impression that the most common planet in the Imperium are the ones designated as Imperial Worlds, and those are generally stable and relatively self-sufficient (as much as any can be in a galaxy-spanning empire).

Agri-Worlds have great potential for expansion, but the only planets I foresee having enormous problems surviving on their own are the Hive Worlds and Forge Worlds, the former far more so than the latter, and I can see the Forge Worlds in particular forming small pocket empires.