Aesthetically speaking, what would differentiate a Forge World from a Hive World (if a specific example is needed to avoid the "depends on the palnet" answer, what would be the main aesthetic difference be between Scintilla and any of the Lathes)? Beyond the copious amounts of the Cog and Skull motif where an Aquila should be, what would truly clue folks in that they are no longer in their version of totalitarian Kansas anymore?

I ask this as I've never put much thought into Forge Worlds before but now that one is looming over my game, all my mind seems capable of coming up with beyond just another Hive World is crazy diesel-punk motifs on some barren rock married to Cybertron. Is there some imagery I can grab onto to give forge words and, more specifically the Lathes, their own character independent of some generic hive world which doesn't involve highly phallic chrome protrusions with cool rings floating inexplicably around them (or robots in disguise for that matter)?

Consider, if you will, that the Hive World is essentially a mass of seething humanity compressed into a space far too small for itself. Hive Worlds exist by being able to spread up and down to accomodate the vast crush of humanity that have made their home there. Whilst aesthetically similar to the Forge World with great tracts of decaying metal and manufactorums left right and centre, the Forge World is less crushed and compacted. Perhaps there you are less likely to find the amenities that you would expect in a Hive World, or that the sounds of life have been replaced by the rythmic drive of machines toiling endlessly in the background whilst hushed servents and tech-priests go about their business.

It's difficult to emphasise the differences between the two types of world since they are basically dominated by the same kinds of terrain, slag wastes, vast factories and towers of metal. The temptation is to lay down a few clear AdMech markers, perhaps titanic machines in the manner of Ordinatus trundling across the wastelands in the distance or a Titan sat atop a great thone overlooking the main city of the Forge World, an ever watchful avatar of the Machine God passing judgement on all beneath its gaze.

I'd assume the architecture to be different. The Imperium always tends toward the Gothic style while the flat Roman one seems more appropriate for the mostly sober Mechanicus.

Further, there'd be much more integration between housing and industrial complexes and more efficiency in general - hab-blocks will be located directly next to the Manufactorum their inhabitants work in and encompass some recreational facilities (as many as the Magoi think your average worker needs) so the menials don't have to waste too much time on commuting.

I would look to the city flyover in Bladerunner, expanded planet wide, with the occasional spire of gleaming super tech stabbing into the sky and great rivers and seas of toxic runoff from the manufactorums. Add in a touch of Orwellian 1984 style supervision and I think you might be on the right track.

Populations would generally be much smaller than a hive world. Also remember that forge born people are tested and categorized from birth into whatever roll they are deemed fit for. There would no upward mobility. The menials would spend the long work shifts of every day working in the same spot on the assembly lines doing the same task day in and day out until their duty cycle (life) expired and they were replaced with another menial. It would be a very ordered, bland, oppressed society, more so than a normal imperial would experience. Everyone except imperials and the rare visitors would most likely be kept on very strict time tables and allowed very little freedom. Servitors would be everywhere, most likely outnumbering people.

Personally I would imagine most forge world cities to be cleaner and safer than most imperial worlds. Until you get out into the toxic wastelands where feral servitors and tech heretics roam wild and are hunted or the forgotten parts of the cities where the feral menials survive. The nice parts of the cities, where important guests are received and the powerful that rule reside, would be fantastical wonders of technology that would stun most who laid eyes on them.

I would also imagine you would be hard pressed to find an Aquilla anywhere outside of imperial and guest sectors.

I'd say a Forge World is a far more inhuman place than a Hive World. Humans define hive worlds, machines define forge worlds.

A Hive World is like 200 Manhattan Islands stacked on top of each other with humans piled into living conditions like Mumbai, the Rio Favelas, or Tokyo, depending on the world, or the level they live on. Think Bladerunner.

A Forge World would be a vast collection of factories and power plants with a few human settlements packed in between them - think Soviet era Chernobyl wasteland regions, or the factories in Terminator salvation, or the remains of Earth in the Matrix trilogy.

The only time PC's in my campaigns set down on a Forge World I described it as a pretty much planet wide factory complex, a bit like a hive world but instead of individual hive spries dotting a wasteland landscape huge smokestacks venting industrial waste gas in the stratosphere replaced them. The entire planetface was covered in huge blocky manufactoria buildings with millions of steel pipelines drawn between them resembling metallic veins, all the while immense Titans stomped about the premises their pilots deftly evading stepping on equipment or buildings while at the same time dodging huge swaying cranearms shifting inumerable tons of cargo. The airspace around the gigantic smokestacks was busy with activity skyplatforms, shuttles and grav-carriages scurrying about like wasps around a nest.

Found som nice inspirational pics on google:

Just imagine an entire planet covered by this stuff, but in ridiculously larger porportions (like a smokestack on one of these pictures might be 100 meters long, a Forge World would have smockestacks maybe one or two kilometers in length instead). Think industrial, think big and you cant go wrong.

The other thing to bear in mind is that the Mechanicus are Priests of technology, and Forge Worlds are the embodiment of their theocratic rule. In some ways a Forge World will bear resemblance to a Shrine World too. I've tended to steer away from the urban decay motifs and more towards vast industrial complexes displaying technology beyond what the cult permits the rest of the Imperium to access, and all of it fashioned as a vast cathedral to the greater glory of the Omnissiah.

I believe RevMarks reply would be the greatest difference. The complete lack of the Imperial Creed and the Ecclesiarchy. And the amount of augmentd serfs (Helot s) as opposed to drudging hive workers.

While I agree that the Forge worlds are going to focus mostly on Omnissiah, there is a huge sect of the Mechanus that believes the Emperor is the Omnissiah so there would be forgeworlds that focus on that aspect as well. While they would not worship him as the Emperor, they would allow and possible encourage the Imperial portions of the forge worlds to follow the Imperial Creed as well as the Mechanicus' 16 Laws.

In my opinion this would create an amalgam of the forge and the church showing Aquillas and Cogs as often as not

wow, thanks a lot guys, especially Varnius for those images (the first is pure gold!)

The problem I have between the forge world and the Hive world is they are both highly industrial and I was needing something I could grab a hold of that would differentiate the two (as my players have just left a hive world, Solomon, and I need something more to illustrate the difference and make the Lathes that much more alein to them). The idea of focusing on more blocky greek or ancient roman construction as opposed to the more gothic construction is a good one as is the brilliant observation and the more efficient city planing (the drones live but a few blocks form work, etc) is something that, while obvious, didn't occur to me. Thank you.

Graver said:

Another thing worth considering might be the difference in urban decay. Hive Cities are notorious for always having a vast underhive and even in the middle hive there are several abandoned manufactoria that have fallen into disuse. This would be highly unlikely to happen on a Forge World (where the only reason a factory or refinery would be abandoned if it is supposed to be torn down and replaced with something bigger/more efficient), in fact i doubt that Forge worlds have anything similar to an underhive at all. Although sewers are bound to exist and perhaps some of the few lawless elements seek what little sanctuary they can find in these areas, they are probably not something comparable to the vast underhives of an average hive city.

Varnias Tybalt said:

Don't forget the Infotombs of Hadd (one of the planets in the Lathes). While not a derelict underhive they do lie beneath several layers of manufactorums and laboratoria and are a rarely visited place, considered a holy of holies by the Machine Cult and rarely visited. Similar depositories of sacred knowledge could exist on other worlds.