A Dark Heresy campaign I am writing at the moment will almost inevitably include some mass combat, and while I'll certainly leave the option open for the Acolytes / Agents to participate, I don't anticipate the battles being their primary focus. Nevertheless, the war will go on.

It's tempting to simply have the battles run in the pure abstract, giving occasional reports that one side is winning, then another, that some push was made or this target was eliminated, and ultimately decide the outcomes on personal whim (or campaign preference). But I believe a lot of the fun of the game, even (or, perhaps, especially) for a GameMaster, comes when chance turns against you. Therefore, I have decided to implement the mass combat rules from Rogue Trader (Battlefleet Koronus).

And so we come to my question: What's your best guess for the number of PDF soldiers on a given hive world? Furthermore, would they be mostly infantry (given the nature of a hive world being mostly urban), or would they employ a standard proportion of armour and artillery (and aircraft)?

As an aside: What other advice would you give concerning the above-stated context?

If Only War had been released, I would post there. Similarly, if Rogue Trader dealt more with colonized and subjugated planets, this question wouldn't be here. I'm partial to Dark Heresy, so I pose my query to you.

Internus said:

Well what kind of planet are we talking about? Because local conditions will determine the type and numbers of the PDF. Roughly I would say that perhaps there are 0,1% of the population might be in the standing PDF force and that could rise to 10% of the planet's population if there is a very real and immediete threat that would justify full mobilization. Given for a standard Imperial world that is.

as said above, what's the world like? A hive world like Valhalla would probably be able to field 20-50% of its adult population as PDF, scintilla might field 0.1%. Most hive worlds produce large amounts of weapons but the sophistication would vary, a rich world's pdf might have pretty much the same equipment as the guard, a poor one's might be armed with stub rifles and have access to very few tanks and artillery. Bare in mind though that even the smallest hive might be able to field Millions of PDF, given the size of the general population, which is somewhat outside of the realm of the BFK rules…

trentmorten said:

I think you're figures are somewhat optimistic. To put it kindly….

Even WWII, the biggest industrialized war the world has had ever seen, didn't reach those percentage figures. Anywhere from 3%-5% of the total population raised for its military is normal in war with perhaps 10% as the upper limit. Germany started with 80 million people and after early annaxations etc. had 116 million as manpower pool and never had more than 9.5 million men under arms (all branches). And that includes young boys and old men in the final year when all manpower sources were utilized….Source: Oxford Companion to WWII.

Taking the Germans as example, you simply can't take that many people out of a society to fight a war and not have that society collapse. Your armies need equipment and supplies and your civilians need food. Germany had to use slave labour to compensate for the men taken out of the economy and had to plunder conquered territories to ship food to German civilians.

Hive worlds will obviously be different as they require regular food shipments and might not actually manufature its own military equipment and supplies but those billions of people will be doing something. So simply putting them in uniform (if you even have enough uniforms) will mean something else will not be produced. And if it is a major war, the first thing an attacker will do is cut off the planet from outside support if at all possible which means the hives will have to start producing their own military equipment and supplies.

Then there is the military aspect of using poorly trained, poorly equipped, hastily raised troops. This mostly just provides high casualty lists, not victory.

Using quantity to compensate for quality only works if the qualitative difference is relatively small. Russian troops in WWII habitually outnumbered the Germans and only suffered ghastly casualties for their efforts. Only when the quality gap lessened (from 1943 onwards) or the strong points of the Germans were negated (as in city fighting) could the Russians compete. Same thing happened to the Iraqi's. They had more men and more tanks than the coalition in 1991 or the Americans in 2003 but never stood a chance.

Raising mass armies is thus not (always) the solution. But you could use it as the backdrop in your game, with a desperate governor raising numerous units only to have them slaughtered on the battlefield without achieving anything.

ranoncles said:

I think you have alot of good points but I think you're selling conscript armies a bit short here. If we're using the German army the Wehrmacht was to my understanding both very qualitative and also very much a conscript army where the soldiers didn't have decades of training behind them, although the officers would probably have more than the average conscript soldier. Just throwing men into the meatgrinder will of course leave horrific causualties, but having to few troops will mean that you either get to spread out or that you can't hope to protect more than a fraction of the inftrastructure that allows the military forces to operate.

Give the raised troops a couple of months or half a year and they should be pretty much fit for action and frontline duty. Most likely the alot of worlds will have paramilitary groups that can be quickly mobilized to boost the numbers of the PDF while larger numbers are being made ready to fight.

Because honestly I can think of few planets which would be able to maintain a permanent PDF force capable of actually defending a planet from, or even slowing, an invader strong enough to make a serious threat. And isn't hat the role of the PDF? To hold the line while untill the Imperial Guard and Navy can arrive to turn the tide. I think it would just cost to much if there isn't a permanent threat hanging over it, like Cadia, and then the world would probably need alot of outsider support between its almost cyclical times of war.

A common nickname (or insult) for PDF is 'speedbump'. Since they usually lack the better euqipment and training of the IG, they only slow invaders down, but too rarely rout them. As for the amount that depends too much on the situation and history of a planet. Besides, serving in th PDF is, like in most armies, not simply being a soldier, they also have their own cooks, mechanics, supply, …

Cadia, as an extreme example, is the most important planet to block Chaos fleets coming from the Eye of Terror. That is a military planet, heavily fortified in space and on ground, and every capable man and woman has to serve. Amount of people in the PDF: ~50% of those who do not serve in the IG or IN.

Scintilla on the other hand has not seen war for centuries, the PDF is usualy busy with keeping food riots down or to crush a few crime syndicates (makes good practice for war, keeps crime low and brings in some money). Amount of people in the ODF: about 0,1% of the world population i'd guess.

Kulth is, with 80 years of fighting the Orks, steadily increasing its number of PDF troops. They could be 5-10%, and if the IG can't take out the greenskins in the next few years will increase that further.

just my 2 Thrones

The location of the war would be similar to Landunder, what I would consider to be a "minor" hive world.

Is 0.1% a good number to go by? That means that Scintilla has a PDF of approximately 25 million. Of course that includes logistic forces (supply, communications, etc.), but that still seems like a lot. This might make sense if PDF were also utilized for minor sector or sub-sector wars, as in the case of a system seceding. But is that the purview of the PDF, or would the IG be called in / formed up?

During the second world war the German economy was widely recognised as not being geared for war until the last two years. Consumer good production actually went up after the fall of Poland.. I'm not sure the imperium produces all that many consumer goods on hive worlds. The imperium has a long history of throwing under trained, under equipped conscripts into battle. Every world has to maintain bodies of armed fighters to fufil the tithe and these reflect on the governor so they are probably reasonably equipped. In a feudal society every noble house would have to provide soldiers as well, although those could well be of dubious quality. I think that governors might be keen to buy assets that couldn't be stripped from the world like emplaced cannons, but that would vary from world to world.

The thing is most worlds of the Imperium are horribly inefficient. It takes more manpower to produce goods than it would for us in the RW. So taking a huge amount of the populace out of the production system isn't really an option.

But with a population of billions that still leaves tens of millions of people in the typical Hive World PDF. However, as mentioned, they are usually horribly underequipped and trained. But you need to remember that this means more than just poor weapons, armour and ammo - it also refers to logistics, transports, command and control. You might have 25 million men, but getting them to do anything is a struggle. You can't just move a million men from one battlefield to another. By the time you manage to move them somewhere the battle will probably have shifted. So they're usually just scattered across the planet at various strategic points and told to dig in and kill any enemies that turn up. Attempts to use them to attack enemies are usually disastrous.

Firstly it's popular opinion that Imperium have terrible logistic. But it's other way around! If you rule country as big as galaxy, where communication depends on sending metaphor of thing you really want (astropath), then some mutant (navigator) must send course thought hell it can be bit tricky to handle it all and all this is managed without computers as they are forbidden. But as we know Imperium stands for 10.000 years, attacked from every side and from within. So please don't say that they have poor logistic.

I've calculated that 10 "best" armies in the world have approximately 8 mln soldiers in service. We can easily add another 8 from other countries in the world, so we get 16 millions men at arms in very peaceful and primitive planet. So in Imperium where dangers is every where and everything is more advance then today (really!) PDF must at least have as many soldiers as our planet have.

It would be a mistake to think that there is such a thing as a "standard" or "typical" PDF. Planetary defence forces are done with whatever the world has. There is no strict structure, as the PDF is not a galaxy-wide organisation.

BYE

While its true that there is no such thing as a PDF like the Imperial Guard I do think that certain trends would be detectable.

coolzyg said:

No, they've got terrible logistics. Absolutely awful. Yes, they've got a galaxy to rule, but their logistics are no where near what they could be. This is mostly due to the fractured nature of the Imperium's government - multiple factions each striving to gain power at the expense of the others. The system is a series of compromises cobbled together into a messy whole. It would require intervention from the Emperor himself to reform, which obviously isn't going to happen.

But we're talking specifically about the PDF here. I don't entirely agree with H.B.M.C's statement that there is no such thing as a 'standard' PDF. While every planet in the Imperium is different and there are exceptions to every rule some things remain broadly similar across the Imperium, influenced as they are by the Imperial Creed and the Adepta. While PDF units can be very different there are some traits that most of them share.

The PDF are a requirement forced upon worlds by the Imperial Creed. But the rules don't seem to say much about what kind of support the PDF has to receive. They are essentially a tax upon the planet, but the planet gets a say in how much that tax has to be. So usually they pay the minimum they can get away with. This is why most PDFs are poorly equipped and trained. Of course there are worlds that have experienced PDFs, or where service in the PDF is an honour etc. But on most worlds the local elites would prefer to raise their own troops rather than pay for more troops loyal to the planetary governor.

The fluff usually depicts PDF as pretty inferior but that is likely so the IG or Space Marines can look even more heroic. If the PDF could easily fight off anything less than a Waaaghhh or Black Crusade, the Black Library would have little to write about :-)

Considering the population levels on some planets, even 0.0001% of the population under arms would lead to huge armies. Nothing wrong with that but that would make 1,000 man SM chapters sacking worlds even more ridiculous. So there has to be some GW reason why planets are not bulging with PDF. I am too lazy to calculate it atm but in WWII, Germany, Russia, Britain & CW and USA had roughly 10 million men each with Japan, Italy etc. at around 3-5 million, say 50 million in total. Add another 10-20 million to include all other armies in the world and you have 70 million from a world population of 2.3 billion.

I would argue the reason imperial planets don't have such huge armies is expediency. The Imperium always needs more men. Beyond the regular tithe, a sector lord may call up additional forces when required. If planet X has a huge, well trained and well equipped PDF while planet Y has civilians with pointy sticks, guess who the sector lord is going to levy for men?

So raising large PDF forces is not a smart thing to do for a planetary governor as they will be taken away by higher authorities. Which means governors will have to figure out the correct balancing act between adequate defence of their planet and too much troops with the inevitable baleful interest of higher powers….

On some over populated worlds the tithe could easily become a method of population control. However, as the quality of the tithe might well determine the life expectancy of the imperial commander then many might give some of thebest they can offer I order towin greater prestige from the wider imperium. PDF is the usual method of training these troops. Of course, they might not call themselves PDF (household soldiers or personal bodyguards) but when the PDF gets called a speedbump let's not forget that this is coming from catachans, cadians, mordian iron guard or other elite formations.

Imperial Governors are required to raise a PDF to the standard of being able to defend their own planet. So its up to you as has been said, paranoid governor might have close to billions, relaxed backwater world might only have hundreds of thousands instead. I think it must be said here as well that PDF are full imperial guardsmen, parts of the tithe can be the folding of whole PDF regiments into the Gaurd, theyre not old men and children. True there would be an additional recruitment of reservists like the T.A. of the National Guard but for the most part PDF'ers are career soldiers, its just unfortunate for them that the rest of the big dark universe is usually either bigger, stronger, tougher, more advanced technologically so they usually dont fare too well.

Banding around real life numbers makes no sense here either, first off we dont have hive cities, the concept of them cannot even be contemplated, imagine 10 or 20 New York's on top of one another and thats a tiny hive population wise. If you do want the conscript route however Switzerland has a 95% conscript army that forms 6.6% of its population at any one time.

Numbers given for the siege of Verunhive on Verghast, the Verunhive PDF numbered 500,000 and the Zoicans 6,000,000, the a good example of the full deployment of PDF in literature of a good sized hive defending itself, utilising the full range of armoured vehicles from battle tanks to support pieces, infantry but no air support as i believe the Imperial Navy kind of has a monopoly on anything that can get off of the ground.

Landunder may only raise a small PDF in comparison to other larger hives as well, but as it has a huge martial background, the close combat skills of even the rawest recruits would be unparalled in comparison to a IRL conscript tithe like the gangs of Necromunda or Armageddon which are pressed into PDF service when the time calls and even deliberately sought out for the draft.

I would suggest that one can draw some inferences from real world military forces and how they interact with populations size.

Let's start with CIA World Factbook. This is an official CIA website which publishes data about the world. It includes data on military forces. Let's take 3 societies in the real world, and compare the size of their military forces.

The USA

To me, I'd say that the USA is probably fairly representative of a peaceful Imperial or Hive world in terms of size of military vs size of population. There are real threats, but no current active full scale war. (Despite the vicious nature of the Afghan campaign, I'd characterise it as a police action in Warhammer 40k terms). The US military plans accordingly. One imagines that most Imperial Governors will adopt a smiliar approach.

The USA has a population of 313,847,465. It's armed forces total 1,458,697. This is about 0.46% of the popluation. In terms of manpower available for military service, there are 73,270,043 males age 16-49, and 71,941,969 females aged 16-49. However not all of these are FIT for military service: these numbers are lower:-

males age 16-49: 60,620,143
females age 16-49: 59,401,941 (2010 est.)

So in the event of a total war, 120,022,084 would be available for service.

Gotta stop here: I shal revert with more points and a comparison with a fortress world: North Korea!

Lightbringer said:

Or try to dig up numbers for the US during WWII. The US was effectively an active fortress world in that time frame, while Europe could be looked at as a war world.

Lightbringer said:

It might be worth remembering that that most Hive worlds, with manpower as one of their major commodities would also be tithing troops to the Imperial Guard. This could be their own regiments or one on nearby worlds.

In you analogy the armed Forces that leave the country would be the Imperial Guard or the Navy and in their Hive world counterpart would never be heard from again. The PDF would be the equivalent of the National guard which is only 467,587 strong, about 0.15% of the population.

It might not matter to your story if the worlds Imperial Guard are around as well but if they are off fighting else where it might.

Final thing, is that in time of peace maintaining a large (several millions) standing army doing nothing is very expensive, especially when generally there might be many years notice of trouble in that sector, where as they are also notoriously hard places to police so you may be likely to find that the percentage of PDF is lower than in the US but the number of Enforcers is much higher.

You know, there's a major difference between the US during World War II and the setting of Dark Heresy.

Women are encouraged/pressed into Active Combat Duty.

Assume 30-40% of the population is within the acceptable age range to be "effective" PDF, and that at least 3/4 of that is going to be put into support roles that would only engage in operations once it's "do or die".

Keep in mind, PDF is probably not going to exclude soldiers because of a single bad joint, or exclude them for having bad vision. They're going to be far less picky over disfigurements and malignancies in a full scale invasion scenario. And there are far fewer "conscientious objectors" in 40k. Well living ones, anyways.

There is one area of attrition that the US never had to account for. The Imperial Navy. How many Hive worlders get pressed into service and are taken off-world? Most of those are going to be taken from the same pool PDF would be taken from, right?

624 said:

I agree with most of this with one exception: Equipment. PDF are not equipped the same as Imperial guard. PDF equipment will be typical for the average tech level of the world. So, for example; On a feral or feudal world the PDF will be armed with Primitive melee weapons (Swords, Axes, etc) or maybe Bows and arrows. On a forgeworld the standard armament of Skitaari (Basically, the AM PDF) is quite superior to Guardsmen! In the case of your Hive, Lasguns would probably be replaced with Autoguns since they are cheaper to issue en mass.

Radwraith said:

While true, a couple of your examples are somewhat off.

Forge Worlds don't produce Imperial Guardsmen - their Skitarii armed forces fulfil both the duties of PDF forces and those of the Imperial Guard within the context of the Adeptus Mechanicus.

Many Hive Worlds are major manufacturers of the bulk goods used by the Imperial Guard - Necromunda produces lasguns, for example, while Armageddon produces a local pattern of Chimera - so those items tend to be in common use by local PDF forces because the surplus is readily available for that purpose. Beyond that, many worlds that produce a standing tithe of Guard Regiments will tend to equip and train the local PDF as close to Imperial Guard standards as possible to allow for ease of transfer. Finally, the lasgun is significantly cheaper than the autogun, particularly large-scale. Autoguns are simpler to manufacture individually, with many being the product of illicit gunsmiths and the like, but lasguns are mass produced on a colossal scale and are logistically far superior to autoguns (which are typically heavier, require greater maintenance and utilise bulky solid ammunition rather than rechargeable power cells).

N0-1_H3r3 said:

That's true, as Redwraith said they tend to be typical of the planets tech level, which is true in this case. Most common technology is made on hive worlds, including Lasguns and Flak armour. So many hive worlds will have PDF equivalent to the common guardsmen in a lot of regiments unless there are environmental or economic factors (they might, like Gunmetal City on Calixis are known for their as producers of firearms). However they would still be lacking on the more specialist and expensive gear that is usually only produced on forge worlds, such as plasma and melta weapons.

I think PDF are traditionally associated with auto-guns because they can be made locally without advanced manufacturing facilities that hive worlds have. Thus many more worlds PDF can be supplied from home.

Face Eater said:

Exactly what I was getting at! (Although I may have not expressed as well since I was in a rush.) The Imperial guard mandates certain standards of equipment and training. For equipment, the standard is a Lasgun and Guard flak armor. For training they are minimum stat levels in WS, BS, S and T of approximately 30+ . Certainly, Forge worlds and or Hive worlds can meet or even exceed the equipment standards while Feral and Feudal worlds easily exceed the physical requirements! (That's why the Sm's like to recruit from them!). It is the job of the Adeptus Munitorium and the Commissariat to ensure that a newly tithed regiment meets BOTH minimum standards! (Either by reequipping a new regiment or remediating there training.) It is the responsibility of the Local Imperial governor to ensure that Tithed units are "Worthy" to be brought up to Guard standards. Again, a Hive world's PDF probably has all the trappings of an IG unit because these units will be tithed to the guard as necessary. As to numbers in the PDF that number could vary considerably based the threats in the area. Remember that the vast majority of urban "Pacification" is handled by enforcers and Arbites and NOT by the PDF! PDF numbers will be based on threats to the world. If the world is fairly Isolated from conflict their PDF will likely be relatively small. If it is in a Warzone then the PDF will be much more substantial. Also bear in mind that the Overall size of the PDF will not likely affect the numbers your Acolytes encounter during their adventures. Military assets are deployed according to the intrinsic strategic importance of any given area. If your group is dealing with an area the military has deemed non vital then it is unlikely your group would encounter more than a squad (10 men) in the area. Conversely, If your group decides to have a firefight in or near a command center or HQ they could easily be fighting "Hordes" (Per either BC or DW)!

ranoncles said:

There's that. Though just as often the PDF ends up being heroic as well in the face of danger, at least to some extent. Purging of Kadillus for example, the Dark Angels are the heroes, but the PDF are a necessity too. Or Rynn's World, where Marines were the focal points of the line, the mobile reserve, but the PDF still did a lot of the mass killing.

Considering the population levels on some planets, even 0.0001% of the population under arms would lead to huge armies. Nothing wrong with that but that would make 1,000 man SM chapters sacking worlds even more ridiculous. So there has to be some GW reason why planets are not bulging with PDF. I am too lazy to calculate it atm but in WWII, Germany, Russia, Britain & CW and USA had roughly 10 million men each with Japan, Italy etc. at around 3-5 million, say 50 million in total. Add another 10-20 million to include all other armies in the world and you have 70 million from a world population of 2.3 billion.

That's seriously true. I often think Marine Chapters would make infinitely more sense at 10,000 strong given the scale of things that happen. An even using the whole 'scale' thing where Marines are worth 100 normal troopers… they sure drop easily enough to normal heavy weapons. But at 10,000 strong a chapter,. Not only do their numbers reach a point they could compete, but some of the "these guys are all over space!" aspects where the named chapters end up in every war… EVER a lot more feasible.

As it stands, they're superb special ops. You CAN rely on them to accomplish objectives. But 1000 Marines in pitched battle? Sorry… ain't happening. Any time you end up in a situation where 100+ enemy troops can bring their firepower to bear per marine… not a chance. But bringing a world to its knees? OK, I buy that, since it basically means crippling the Command Structure of the worlds' armies and government, just not wiping out the armies. They'd need serious IG or even Chapter PDF style troopers for that. There just aren't enough to bring a world to its knees otherwise, it's no indictment of the Marines' combat ability, just simple numbers and how they can't be in nearly enough places to make a difference even with Teleportation tech and such.

Though that said, the Iraqi wars are good examples of how mobile and potent a well trained technologically superior force against a not quite as advanced one can work. And Marines are super mobile, modern warfare is fought over gigantic fronts (Nothing like Waterloo or Napoleonic era stuff, where 100,000 troops a side might well be in a few mile radius, no, in this sort of warfare, 100,,000 troops will probably be spread over a hundred miles or more because any closer and it's stupid easy to kill them all with artillery and rapid fire weapons. And that's when 1000 Marines, or even 100 marines can easily bring superior firepower to bare.,

EDIT: Another interesting Factoid to throw into the Mix. Police Forces. These aren't quite military well trained for combat, but you can damned well bet in an invasion situation they'd be a major combat factor. Why do I say this? Well, New York City's police force, if counted as an army, would be the third biggest army in the world. So imagine a Hive World's police forces - while still likely mainly trying to maintain order in the face of utter chaos, are a potentially big combat force too.

Also, in regards to the 'poor training' thing some mentioned about worlds. What about worlds that work like Israel or Switzerland, where everyone has to ahve a mandatory period of military service. Sure some of the conditioning would be gone, but those could be a damned effective reserve force in the face of total world war invasions from Ork Waaaaaghs or 'nids and the likes.