Reading the section on Warp Travel and Communication in Chapter 9, how does the Imperium even exist?

Seems you could send a fleet off to deal with a rebellion and there is no way of predicting when or if it will arrive.

In the chapter on warp travel it says that time does not act normally, that centuries could pass, or mere seconds, or you could arrive before you left. Also that "Even skilled Navigators cannot predict how much time will be lost, gained or repeated over the course of a journey." And that's travel under normal conditions it gets worse if there is a warp storm going on. How could you possibly hold an empire together if that is the case?

That's before we have even taken into account communication. How do you even hear of this rebellion in the first place when communication is either by warp travel which has the problems mentioned before or by astropath. One example of Astropathic communication they give it takes the astropath years to even prepare the message for sending, even quicker methods of communication aren't like a telegraph, more like an extended game of Pictionary mixed with Chinese Whispers for each phrase. That's assuming the symbolic message gets to the intended receiver, often it doesn't, even when it does it can take weeks to interpret if it is ever understood at all.

So assuming a rebellion starts it takes months to years for the governor to send a message for help, and assuming it ever arrives it might take the same amount of time to get a message back to say help is on the way. Then the help might arrive weeks before the help was requested, or centuries after, or not at all.

Is any of this reflected in the game rules? I imagine it would need to be in Rogue Trader (I don't own that yet), or is it just a handy way for the GM to say you arrive when suitable to the plot, and to stop them crying to the Inquisition for help whenever things get tough.

Well, all of what you describe is indeed a problem for the Imperium and the reason why it is hardly holding its empire together and why most things take ages within the Imperium on a grander scale (and also why it is rather fragmented and sometimes heterogenous). You even forgot to mention the meticulous way the Administratum works, so that even if the message finally arrives at lets say the Segmentum command, it often take ages for the Administratum to work on it and come to a decision. Still, rebellions take place all the way in the Imperium for the very reasons you mentioned and often the Imperium acts decades or even centuries later but then mostly with their full might. The Inquisition (i.e. Inquisitors) on the other hand has the advantage of not having these huge bureaucratic hurdles and so is capable of acting surprisingly fast most of the time (at least in comparison to most of the other organs of the Adeptus Terra).

But let’s see whether I can alleviate some of your specific concerns. Regarding Navigators, there are many stable warp routes between planets and even sectors that are considered as more or less stable and highly frequented so that it is even possible to use them without any Navigator in the first place, but by calculating short successive warp jumps. Less stable warp routes need the use of a Navigator, and even though he cannot predict a definite time when the ship arrives or how much time will be ‘lost’, most experienced Navigators can predict it rather well. Imagine a navigator on a sailing ship in the 17th century; he certainly could not predict the time of arrival on longer journeys either, especially if in unknown waters. But then the British Empire(s) held together quite well for a time even though it had sort of similar problems.

Regarding astropathic communication, I think the DH rulebook exaggerate the way it works a little. In many other 40K literature it works a little less difficult, takes a little less long and is a little clearer than mentioned there. Still, it takes a while and is not as easy as simply sending a telegram as you already mentioned. But then, the Adeptus Arbites fortresses situated on most imperial planets almost always have their own Astropath or astropathic choir, for the very reason you mentioned and because this fortress is often what holds out longest if a planet falls to rebellion (so the Arbitrators simply buy time for the Astropath to send his message – one of the devious ways the Tyranid hive mind works btw is that it blocks this very form of communication due to the shadow in the warp, so that the astropathic plea for help will never arrive anyone…but I wander off topic…).

After all, the help might arrive after centuries (or not at all) and this is often the case in the wider Imperium (and that is what 40K is often about). Help arriving before sending for help is a temporal paradox that does not seem to happen that frequently in 40K as far as I recall. Delay is far more frequent, and especially for warp travel time seem to almost always travel slower in the warp than without (i.e. 2 months in the warp might be 2 years in real space, but seldomly the other way around).

One has to keep in mind that most Sector governors “govern” without much contact to the rest of the Segmentum or even Terra and the rest of the Imperium.

Still a wonder that the Imperium exists, but actually it hardly does and that is one of the main themes of 40K…

Luthor Harkon said:

Although to be fair 2 years is still arriving considerably faster than if they had travelled via non-warp methods. Even arriving centuries later would be faster than sub-light speeds.

Remember the scale we are talking about. Sure, it might take months for nearby worlds to properly react to a full scale rebellion, but that is not all that much considering that the rebells are trying to take over an entire planet. It takes some time to gain control.

British Empire managed to hold together during the ages of sailing by basically trusting on navy alone. With pre-modern navigation and weather-prediction methods that meant that ships would arrive weeks or months late... or never. Still, they did manage to hold the Empire together. Much in Warhammer 40K starts to make sense only when you throw out all pre-conceived notions of "modernity" and think it more in the terms of 15th or 16th century colonial empires.

Let's also not ignore the fact that the Imperium flat-out doesn't care about many rebellions - as long as the rebels plan to continue remaining within the Imperium and paying their tithes, the Imperium (or rather the Inquisition, usually) may even support the rebellion.

True that. Isn't it in Maggots in the Meat the Administratum is actually playing all three sides in a planet wide civil war since all three sides try to outdo the others when it comes to paying tithe, in order for the Imperium to side with them. Triple the tithe and no need to send troops there

Honn said:

Yup. Exactly. Long as the tithes are coming in as expected ... or better ... meh. Let 'em play.

How can tithes come as "expected" when you can't accurately predict travel times?

Lot of it comes down to massive exaggerations by fiction writers that dont necessarily make examples easy to live with RPG'ers. Such said examples could be best compared to fanciful drunken sea travellers tales of ancient and terrible monsters, ghost ships, mystery islands, alien cultures and other strange things that for the average dense imperial yokel probably takes completely for face value. People in the imperium are close minded, ignorant and deliberately kept ignorant for their own good, they aren't technical, they aren't widely educated and they're certainly xenophobic in the literal sense that strangers are really strange and best avoided.

"Hey pa, this old geezer at the pub reckons they arrived before theyse left to get to here!"

*BAM* "Quit yer diddlydaddlin and get dem sheep in the house paddock afore I 'its ya again!"

But they are resiliant and self reliant in so much that planets know they could be on their own for a very long time before any help arrives, if they cant deal with it before the help arrives, they die, there is no way off to safety. The fact they can call on help from the Imperium is also technically WHY they remain part of the Imperium because if they aren't, they'll be either crushed as an example and made to comply, or left to the wolves... or in the 40K sense, the Xenos, Heretics and worse.

So as far as warp travel is concerned, yes it entirely possible the warp can delay or advance an arrival somewhere by huge factors. However when it does, its best considered an extreme example of the fickleties of wap travel rather than the normal occourance... but all the stories are true about it being terrible and weird

NTLBagpuss said:

It's not quite that bad; it fundamentally can't be for the Imperium to function at all. Rogue Trader presents the matters of warp travel and interstellar communications in more detail, given that Navigators and Astropaths are player character choices in that game. A skilled Navigator can make a decent estimate of travel time (which will still only ever be an estimate), and may even be able to reduce the time spent in the Warp by a considerable degree if sufficiently capable.

NTLBagpuss said:

One of the reasons that Astropaths are so essential. Broadly speaking, you'd never rely solely on a single Astropath for everything - the work is taxing and difficult at the best of times, and few Astropaths have the power to send messages over really long distances. Instead, Astropathic Choirs are employed, using many weaker Astropaths to provide power for a single more skilled one so that a message can be sent, normally to a relay station (manned by more Astropaths), where it can then be sent off towards its destination, or to another relay if the recipient is a really long way away.

As described in the novel Blind, the biggest Astropathic facilities (such as those at the heart of an entire Segmentum Majoris) may contain thousands of psykers with an elaborate support staff to assist the Astropaths in any way necessary. The use of such individuals is not a simple or small-scale matter, and for good reason - the Imperium would collapse without their efforts.

NTLBagpuss said:

It's covered in Rogue Trader, but from the perspective of Dark Heresy, it's just a way to convey the relative uncertainty of the matters (a little exaggerated to get the point across; this isn't Star Trek or Star Wars where travelling and communicating between worlds is fast, easy and safe)

Added to the point of scaling (that a rebellion to take an entire planet would itself take a long time) you can't forget Planetary Defence Forces (PDFs) whose job it is to quell such rebellions. Any Imperial world worth its salt, and therefore, worth being protected has a PDF which should be sufficient to quell any insurgencies in the population, which is exactly the reason why Chaos often works via secretive cults instead of all out planetary invasions, because there are just so god damned many Imperial Guardsmen under the Imperium. Further this means that the heretics often have to infiltrate the PDF to take a city/hive/colony/planet.

That being said, I am sure there are worlds in the galaxy that are still paying tithes and pretending to be Imperial whilst harbouring large (maybe even invasion sized) forces of heretic troops... There might even be some in the Calixis Sector.

As they say, Sci-Fi writers have no sense of scale, so you have to scale everything back a bit for it to make sense

It's like with Hive Sibelus. If you look at the description it is absurdly huge. In fact, it is slo large that if you do some math you find that the Hive has an average population density that is lower than some real-world countries. And all that is assuming the hive is totally flat (only a single floor). But of course it isn't flat, it is very tall, and when you also take that into account it ends up with a population density that is lower than real-world earth (I think both counting only earth land-area and the entire area). Which means that some writer decided that "this Hive is going to be huuuuuge!" and then set a number without actually thinking about what that would mean.

Polaria beat me to it.

The thing to remember is that the Imperium is kept together not so much by fast response, but by common worship, technology, the bureacracy and the Astropaths.

Much like culture and nationalism were the building blocks of old world empires (An englishman was proud to be an englishman, and nothing was quite so hated or despised as the traitor), the Imperium is just held together by slightly different ties. The ecclesiarchy, the adeptus mechanicus, the administratum and the astra telepathica do more to glue the Imperium together then the Imperial Guard or Navy. They provide the fabric that keeps humanity the emperor loving (or fearing), proud and fearful star empire that it is.

Its an interesting sci fi twist. And not necessarily one that is very realistic perhaps, but it does make the setting very identifiable and in some ways personable. Most of your classics can easily be translated to DH (or already have been in various forms by Black Library authors), so there's a great deal of common cultural concepts that we can identify with. Rather then the near transhumanism of other sci-fi games, DH is way more gritty and should be taken as such.

Just my 2 cents.

Honn said:

www.fantasyflightgames.com/edge_foros_discusion.asp

This link is to an ancient and long dead thread where we hashed out the numbers regarding Hive Sibelius.

Reading the Core Rules on Malfi it says: "This hive world, eight hundred days standard from Scintilla" So most warp travels between those places takes more then 2 years. As I want to have my players visiting different worlds during the campaign, and also being able to move to respond to some threats. I think this takes much to long time to be manageble. Although I want travels to be dangerous and a bit unpredictable. Maybe 80 days would be more appropriate.

Yep, its just 90 days in my game on an average trip, fantasy writers are excitable creatures when it comes to big numbers and Malfi 'isnt' that far away.

reptile74 said:

Well, most bulk cargo freighters without any Navigator on board and using the relatively safe standard warp routes maybe need about 800 days on average. They have relatively low powered plasma drives so need many days to reach the edge of a system (and thus a viable warp entry point) for a 'safe' warp transition, then en route they have to transfer back to real space from time to time to check whether they are still on course and to adjust their bearing, and reaching their destination they again have to crawl from the systems edge to the planet itself. An Cobra Destroyer of the Imperial Navy on the other hand might risk an emergency transtion near to a stellar body (i.e. no need to reach the edge of the system with conventional yet powerful propulsion) and with the help of an able Navigator might adjust bearing within the warp and might use a more 'direct' route through the warp (and its more hazardous currents) towards its destination where it re-enters real space all within only 80 days.

It is like with sailing ships during the Age of Sail where a caravel or carrack would have taken rather long to reach its destination (and might have problems with high winds), while a military frigate would be much faster (especially with an able navigator and crew) and brush off any not so serious storm and even make use of high winds.

Shouldn't RT have something to say about travel time and how much a skilled Navigator can shorten the time needed? I have just skimmed the book a bit, but I think there is a method somewhere for calculating travel time.

I remember an old thread on these travel times, and we concluded that the whole "800 days standard" thing was best forgotten and ignored. It contradicts everything else published on travel times, including info on the Misericords travels, and simply makes no sense. Nowhere is a "day standard" defined, either.

And that old thread is here .

For some reason the forums mangled my attempts at making tables in that thread, but the excel version of the travel-times chart can be found here .

First of all.. in the dark grim future of the 41st Milennium, there is no realism. There is only war!

But there are some issues that might not have been considered:

1. "Divided we stand, united we fall!"

The Empire is not run by a single man, or even a single group of people. The impossible huge Administratum is suprisingly independent in their locales, so cryes for help against a large invasion of a planet needen't go that far (certainly not to Holy Terra). Also, since rebellions can usually be put down by local forces, which can communicate with eachother in real time over vox... Each Sector has it's own fleet as well, which can probably respond anywhere within the Sector in months if not weeks...

2. "Men must die so that Man survives."

Despite these safeguards, mistakes are made, and in rare cases rebellions or xeno incursons..

Darth Smeg said:

I'd assume that a 'day standard' would be 24 hours, Earth hours, given the Imperium teaches the worship

of not just the Emperor but that Earth is the holiest place in the Universe.

And longer travel times make sense for ships one step removed from a space hulk and not using a Navigator,

but mostly they should be adjusted to suit an idividual campaign.

Most stuff is just exagerated to silly levels though and needs toning down to make sense.

The imperial standard-day is 8.76 hours long, so the 800 days (imperial) convert to 292 days (24h). This is a lot closer to travel times mentioned in books like Eisenhorn and the like.

NTLBagpuss said:

Is there anything saying the tithe has to go through warp? Couldn't it be bound for supporting other worlds within the sector?