What do people know about where things are manufactured in the Imperium. More specifically, Hive worlds are often cited as producing much of the Imperials goods but what can only be on Forge worlds, and is there any thing that is mostly made on Industrial Imperial worlds?

For example, Gunmetal Hive is renowned for it's firearms, so pressumable most firearms are made on Hive worlds. In the main rules (I think) it mentions that pretty much each Forge world has it's own (probably almost identical) pattern of Lasgun.

Vehicles for instance. Are Chimera's or Rhino's restricted to Forge worlds? I know many tanks have a Forge world pattern name (Ryza, Vanaheim) but occasionally you see a Hive world pattern (i.e. Armageddon). Does this mean Hive worlds can produce armoured vehicles or were they created on a Forgeworld specifically for the Armageddon war('s) or where they only changed on the Hive world it's self.

As I've understood it most Imperial worlds can produce most of the stuff that they use in daily life themselves while the Forge Worlds have a monopoly on the really advanced technological stuff. Thus I would say that most Hive Worlds have some serious industrial capacity but probably not the same technical knowhow that a Forge World has.

Production on Hive worlds (and other Imperial worlds) is done under the authorization of the Mechanicus. A specific Manufactoria (or more likely its owning house) would have negotiated a compact with the Mechanicus for the license and blueprints for certain items, and would produce only these items. Items that aren't "technology" (ie most simple mechanical devices like food processors, simple combustion engines, etc) could probably be produced without such agreements.

All of the really advanced stuff are produced by the Mechanicus itself, on it's Forge worlds. Stuff like starships and Titans, etc.

One thing that helped me get my head round this area is the idea of "archprints."

Archprints, as I understand them, are the Mechanicus' own interpretation of Standard Template Construct (STC) designs/blueprints. As such, they are second hand copies of ancient technical readouts from the dark age of technology. Different Forge worlds will have different archprints, hence different "patterns" of design. One forge world might produce a Rhino of a certain type, another might produce one that has a different appearance, but with broadly the same capabilities and performance.

Forge Worlds hold hundreds of archprints for many different classes of Imperial technology. Virtually all forge worlds manufacture goods, but they may, in effect, "contract out" the manufacture of certain components, technology vehicles etc to other industrialised worlds. The manufacturing facilities will always be supervised by the Tech Priests themselves, but it would probably actually be run by the planetary authorities.

Recent setting material emphasizes the way in which the Adeptus Mechanicus ties itself into mainstream Imperial society through binding oaths and contracts. An example might be a compact beetween a hive world and a forge world: the Adeptus Mechanicus might agree to construct a factorum based on the hive world which will then manufacture military vehicles. The hive world in exchange provides a set number of military vehicles per year to the Adeptus Mechanicus' Tech-Guard reguiments, and may also send the Tech Priests a portion of their prison population every year to convert into servitors. The arrangement works to their mutual benefit: for a couple of years' work for a couple of dozen tech priests, the Admech gets tanks in perpetuity and a steady influx of servitors. The Hive world gets ready employment for its people, an increased tithe rating (and as such better protection from the Imperium) and more wealth and prestige for its noble class.

EDIT: so in answer to the original question, both Forge and Hive worlds are fully capable of producing advanced Imperial Tech. The difference between a Hive world and a forge world rests more in the nature of the planetary government than it does in the cosmetic appearance of the planet or its manufacturing capability. There are other differences, of course: hive worlds are more heavily populated, forge worlds are more orderly etc, but at a certain level the two types of planet can be quite similar.

As to why you might get "Armageddon Pattern" Imperial Tech, one imagines that the archprint for this design was created wholesale on Armageddon in an Adeptus Mechanicus Templum, and as such is named after the world of its origin.

EDIT AGAIN: And to develop this idea further, one imagines that there is a rich trade between forge worlds in archprints or the right to use archprints for manufacturing purposes. Individual forge worlds may actually go to war with other forge worlds over the posession or moral right to use these ancient scraps of parchment.

As well do consider that the Admech are essentially secretive wizards. They hoard knowledge and power and do not like to share either with anyone, even each other.

Take for instance Ryza. For some reason Ryza do plasma based tech very well. Most likely they found something like the sargon fragment but for plasma tech, some ancient treatise on making advanced plasma weapons. While Ryza are happy to contract out the making of tanks, lasguns and so on, they realise that they have an edge in plasma stuff and ONLY they make Ryza class weapons. Since Ryza weapons are better, everyone who wants and can afford them buys from Ryza. This makes the techpriests money and power. The possibility of industrial espionage means they are very unlikely to contract out the designs for the plasma weapons they are known for.

Most forgeworlds might be expected to have a few "super designs" that they will not contract out and hundreds or thousands of lesser designs that they will. Thus something like the Ryza class plasma pistol is a rare and wonderful device that was definitely made on Ryza.

The armageddon class lasgun on the other hand was made under contract on Armageddon, maybe designed by a local tech-priest. It was made in vast numbers by the hive world and exported massively across sectors. Being a well made gun, the admech contract the design out to other interested hive worlds. Thus the Armageddon class lasgun is a popular design, that might have been, but isn't necessarily made on the actual world Armageddon.

Thanks to you all, that's all makes a lot more sense now.

As it seems that most technology is not irreplacable do you think some forge worlds have irreplacable ancient machines? Say forge world X has a certain reactor required to make essential componants of statsis technology, for example.

What is likely to be ONLY ever made on Forge World? Plasma weapons, Powerfields, Melta weapons?

I think Titans are Forge World exclusive as well as most Landraiders and other super heavies...

I wouldn't rule out a Chapter's Forge being able to build Land Raiders and other high-tech stuff (Land Speeders maybe, Thunderhawks), just that the larger stuff tends to tax the production capabilities, so they usually contract it out to the Mechanicus.

But anyway Plasma Weapons, Titans, energy shield and gravitic technology, all the real fancy parts of a starship of course, superheavy tanks, and so on, are manufactured in-house by the Mechanicus. It might not always be in a Forge World, but it will be in a Mechanicus owned factory, as opposed to one they just lease out the designs too (even if they do have near-control over those as well).

Some of the marine chapters are almost completely self sufficient, Raven Guard and Salamanders I believe can make the more advanced wargear and vehicles.

One concept I came up with when I was making up my heretek's history for BC was "Offworlding". All the really annoying things about sending a contract offshore for tech support mixed in with developing-country levels of production quality and lolwut levels of OH&S. All the **** you wouldnt bother throwing the real estate on a forge to do (bullets, stubbers, flackweave, toasters, sporks, lightbulbs, simple IC-engines, starship paint, explosives etc) and then send a tech-priest or relatively rubbish magos there to oversee it so the local cretins don't screw it up too often.

Sometimes, if they're bored, bribed or sufficiently chem-whacked, same said rubbish magos might licence a local company to make something on their own to-spec like Malfian dueling pistols, chrono's or cogitator components.