The Wilds
"No map can accurately represent the Wilds and so we write: Here There Be Dragons."
The Wilds are the natural state of the world -> changing landscapes, dangerous creatures and pure chaotic beauty. An adventurer venturing deep into the Wilds could walk the same way two days in a row and one day end up in a beautiful forest and the next day end up in Hell. People have always created pockets of civilization however and areas that are marched over and over again, areas that are mapped and considered a place, areas that are believed to be "home" become stable and fixed points. The farther one gets away from a fixed point the "wilder" the Wilds become.
Imperial citizens grow up on terrifying tales of the Wilds and many of them are true to a degree, but people do not realize that the Wilds are everywhere -> below the ground in labyrinthian catacombs, up in the sky in floating castles and yes, outside the borders of the Empire. The battle against the Wilds is never-ending and many religions believe that one day the Wilds will simply reclaim the entire world.
The Empire
"And Lo!" Said the Saint Tara, "For I have seen the chaos and suffering of the Wilds and yet I have seen Man strive to settle it nonetheless. And so I declare- there will be an Empire from start to end of this world, mapped and ordered, safe and free such that no child will suffer to know the deprivations of what has been..." - Founding myth of the Empire
"And what did the Empire do? March in and destroy our city all in the name of order, then abandon it once again to the depravities of illusionists. Order they say? We were plenty orderly on our own." - Mirror City oral history
The founding myth of the Empire goes something like this: Once, there was nothing but the Wilds and pockets of civilization. In one of these pockets (what would eventually become the capital of the Empire) gathered the seven Saints. They saw the chaos our world lived in and knew their cause- to establish an Empire of order, to link every piece of civilization to each other, to wipe out every last trace of the Wilds. People saw their burning cause and flocked to them. Together, the seven Saints created a new civilization like none before, sealed with righteousness and purpose -> the Empire.
The reality of the Empire... well it may be a little different.
The Empire is a theocracy ruled by the religion of the Seven Saints, managed by a council of the heads of the religious orders and many many bureaucrats. At this point the Empire is more a loose collection of territories bound by a common religious and cultural touchstone + a nominal government.
All player characters born in the Empire are considered Imperial Citizens. As Imperial Citizens they gain a Spear Proficiency (the better to be conscripted), the right to be tried under the Empire's laws (including the conscript laws) and the right to be conscripted at random by the Imperial military. Still, life in the Empire is often considered much better than attempting to make it on your own in the Wilds. The citizens of the Empire are primarily Humans and Orcs.
The Borderlands
On the outskirts of the Empire lie the Borderlands, part civilization and part Wilds. This is the area that is only barely tamed and this is the area in which the forest elves live in various tree cities. Brought under the Empire's sphere of influence by Rath the forest elves maintain an uneasy allegiance to the Empire, though some elven settlements are stoutly anti-imperial and claim to have never been conquered.
Even the friendliest forest elf settlements are aloof and often unwelcoming to visitors, but they are far more pleasant to encounter than the Wild Elves that sometimes venture out of the Wilds into the Borderlands. Wild Elves are not so much elves as they are undying vicious fey, prone to sadistic mischief and unconcerned with morals. Occasionally a forest elf will go "wild" and spend many years with them. Some never return to the Borderlands or civilization.
Recently one of the larger elvish settlements was taken over by the Wilds (though some anti-Imperials might prefer the term "reclaimed") which has caused a lot of alarm among the Imperial troops in the area.
The Orcish Isles
One of the early conquests of the Empire, the Orcish Isles are the original home of Kali and Kali's Legion. The orcs there (though not just orcs live there) are proud seamen and many go on to become privateers (aka pirates, but sanctioned by the Empire). Pre-Empire they spent most of their time feuding with each other. Now, with the help of the Empire they instead spend most of their time subjecting other places, whether that be via Kali's Legion (of which the Orcish Isles provides the most members) or through more personal adventuring.
City of Umon
Deep in the desert lies the City of Umon, home of the desert elves. It is almost impossible to find the city without the assistance of a member of the Pathfinder's Guild who jealously guard their pathfinding magic. The City of Umon is a theocracy of sorts -> it is ruled by the Priests of Umon, also known as Diviners, who worship the pursuit of knowledge (and the hoarding of it) as declared by Umon. Umon the entity (who is not Saint Umon despite having the same name) does not reward worshippers. In fact, Umon is more of a concept, a piece of the world before with unknowable power and no way to be comprehended by mortals though that doesn't stop them from trying. The center of the City of Umon is Umon's Library (also not named after Saint Umon. The name Umon is the most popular name in the City of Umon which causes much confusion among those who do not reside there).
At one point the City of Umon used to be the gnomish Oasis City but very few people know that. If the Priests of Umon had their way, no one would. Those in the know believe that Umon's Library is actually the largest piece of the Clockwork to still exist.
The City of Umon is technically allied with the Empire but has an uneasy relationship with the Empire as the Imperial Government has always made their wish to rule the City of Umon rather evident. For now, however, the two co-exist as neither can subjugate the other.
The Library
Umon's Library contains all knowledge, past, present and future, true and untrue... if you are able to find it. An ever-changing maze of rooms, full of dangerous landscapes and creatures, the Library provides untold riches and knowledge and Diviners devote their life to excavating small scraps of knowledge from it. They are aided in this journey by Index and Query, two strange demons obsessed with cataloging.
Indexers are a class of demons; there are many of them in the library. Most of them are unfriendly. They sort of resemble Kamaji from Spirited Away but with a big pig nose they sniff books with. They spend their time sniffing out knowledge and its location. Index is the largest and most powerful Indexer in the library.
Query is unique as far as the Diviners can tell. Query sits at a round desk and their obese slug-like body fills the volume of the round desk with tiny little glasses near where their head seems to be. Query spends their time cataloging the location of knowledge that the Indexers find and will share it for a price.
Outside of the true Library is the repository of knowledge maintained by the Diviners and for those not in the know, this is believed to be the actual Library of Uman. Pilgrims pay large amounts of money to get their questions answered from these catalogs of information.
The Flying City
The Flying City is the last remaining Gnomish stronghold after the takeover of the Mirror City by the Master of Mirrors. As such, the gnomes of the Flying City are very wary of other people and keep the exact location of the Flying City obscured in the mountains of Hive. The Knightly Order of Trackers has attempted to map its location several times and each time, with much force of magic, the gnomes of the Flying City have activated the remaining fragment of the Clockwork and flown the city to a new location. The entire city cannot remain flying indefinitely, but certain important buildings are kept in the air permanently. They are not friendly towards the Empire but maintain decent relations with Hive.
Many hundreds of years ago the Flying City sent off a great expedition to found a new city, sacrificing a major piece of their fragment of the Clockwork to create a massive flying castle. The flying castle launched and was promptly swept up in a storm of epic proportions that had never seen before and vanished, never to be seen again... unless you happen to get lost enough in a storm and end up in a mysterious place called the Eye of the Storm.
The Flying City is protected by their troop of Falconers, masterful Rouge/Fighters who train birds to scout and do various tasks. Troops approaching the Flying City will be harried and destroyed by collapsing cliffs, intricate traps and sniper archers in the night. The Falconers are sworn enemies of the Knightly Order of Trackers (and vice versa) who continue to attempt to map their location.
Gnomes are the oldest race in the world and are speculated to be part Clockwork.
Hive
Deep in the center of a great mountain lies Hive, the foremost city of the dwarves. But Hive is not just a city -> it is the entryway to a labyrinth of mines that contain galleries and galleries of dwarfs.
Dwarfs are an unusual race -> they were formed out of clay by the Craftsman and stacked in galleries. Only a dwarven queen can awaken a dwarf from clay by reading their true name out loud and once she does the dwarf is bound to her and her will, shown through the clan symbol that appears on the palm of their hands. A dwarf takes on the name of their queen and clan as their last name. Access to the galleries are strictly guarded by the Nine Queen Alliance that rules Hive. However, all is not as well as it seems. What once seemed like a never-ending surplus of galleries are getting harder and harder to find, and the dwarven miners in charge of excavating further and further below Hive are encountering more and more dangerous terrain...
Dwarves are not the only things living under Hive. In the catacombs of hollowed out mines live the Clay Trolls. Rejects of the Craftsman, they seek to consume other trolls and dwarves for that is how they grow stronger. If a Clay Troll were to consume a queen they might just be unstoppable...
A queen can be awakened by any dwarf but they are very rarely found in galleries. Dwarven queens are naturally the size of Hill Giants but can shrink at will to the size of dwarves. They are innately charming to dwarves and are immensely powerful upon awakening. While dwarves do die of natural causes at ~150 years old, no queen has ever died of natural causes, though many have died of unnatural causes in the unending power struggles of Hive.
The North
"And then the Frost Giant appeared at the campsite and shouted "Ho ho ho! I smell a naughty child -> my favorite dessert!" and all the naughty children screamed and tried to run away but it was too late..." - excerpt from a fable told to Northern children
"Well their city was stupid anyway. Plus it's way too cold up there. What sensible person wants to live there?" - anachronistic quote attributed to Vash upon learning that the Imperial Legion had once again been repulsed from the walls of Frostpakt Fortress
Up in the Wild mountains beyond the Empire's northern borders live the nomadic northern clans (composed mostly of humans and orcs); also various terrible creatures like Frost Giants, demonic even-toed ungulates, enormous ice snakes that can swallow a horse whole, etc.
The nomadic clans maintain only one (known) stronghold against the Wilds -> a former Frost Giant castle called Frostpakt Fortress. Long ago the clans came together and evicted the previous occupants; it remains a place where all northern clan members can gather in peace and trade and interact to their heart's content though non-clan members are rarely welcome within the walls.
The northern clans and the Frost Giants are sworn enemies and will fight if they encounter each other.
Life in the northern Wilds is very tough and so the people that live there maintain a strong tradition of hospitality. They learn to ride sturdy mountain horses from a young age and survive well in cold and mountainous terrain. The clans mostly follow various nature or ancestral patrons and are a common target of missionaries of Kali. Many of the northern clans have a neutral relationship with the Empire, with most Imperial citizens regarding them as barbarians if they know they exist.
The Mirror City
The Mirror City was one of the four great Gnomish strongholds, built around the Great Mirror which powered their strong illusion magic. When the Empire decided to annex the Mirror City, the gnomes living there used their piece of the Clockwork to defend, creating hordes of shadowy monsters that decimated the Imperial Legion. During this battle, Sona took advantage of the chaos to sneak into their stronghold and gain control of the Great Mirror. As she studied it, she realized that the use of it (including hers) was creating an even more dangerous evil -> the Master of Mirrors. Before the Master of Mirrors could emerge she shattered the Great Mirror, allowing the Empire to take over the Mirror City, and creating thousands of doppelgangers of herself, one for each shard of the Great Mirror.
Over the next few decades the doppelgangers ate each other, growing more powerful as they consumed each other. Eventually the largest shard claimed the title of the Master of Mirrors and uniting the remaining anti-Imperial sentiment, managed to sever the magical ties to the Empire and allow the city to retreat into the Wilds.
The Mirror City is now a very dangerous city, full of illusions and deadly magic and ruled over by the capricious Master of Mirrors. Despite this, those who wish to study high level illusion magic will need to spend some time there. The Master of Mirrors has a complicated relationship with the followers of Sona - after all, they are a reflection of her.