Much smaller, these are notes for an ancient astronauts type game. Feel free to grab and use...
Earth, one heck of a long time ago. It is a planet ruled by an alien race that we will, for now, call the Deva. Beautiful, tall, powerful and domineering the Deva are the creators of humanity - they took Neanderthal man and produced Homo Sapiens from what they had. They also span off a number of different castes that were tweaked to suit their needs - Giants, Psykers, Soldiers and, rarest of all, Technicians. They use these groups to support their hegemony. Supremely skilled geneticists the Deva have also created monsters and creatures to battle for them in the arena, to serve them on the hunt and to be their guardians.
On Earth, they are devoted to extracting resources to send back to Homeworld. They have established cities on the planet to facilitate this and also maintain a base high above the planet, in geosynchronous orbit. Aboard their spaceship, they hold conference and decide the fate of the world they have enslaved.
Meanwhile, another alien race, the Raksha, have infiltrated the Earth. A race of shapechangers who have been at war with the Deva for many generations, the Raksha have become feral and savage. Their only interest in the planet is destroying the Deva presence here, but if that means reducing Earth to rubble, they're willing to do that. Unlike the Deva the Raksha are strictly Earthbound, operating out of the Himalayas and other mountain ranges, seeking to infiltrate and disrupt the cities the Deva have built.
As for humanity? They labour for their masters, breaking free where possible but still largely enslaved. They live, die and breed for the Deva, their Gods. And some of them dream of better days when they will be free. Rebellions grow in the shadows, armies of free tribes gather in the north and south among the ice sheets and hot lands. War is coming and the Gods may find their children are less grateful than they imagined.
The world is trapped in an ice age (during the Age of Leo, maybe, since this is alternative archaeology nonsense), the sea levels are much lower than they are today and as a consequence, most of the locations used in this project are probably now underwater. The central location is in what would now be Cuba and the surrounding area; in what is at the time of writing the city of Atlantis. This city hosts not only one of the strongest alien presences on Earth but is also the home of a psychic conspiracy to overthrow the Gods and take control of the Earth by the Psyker caste (the conspirators seek to inherit their masters' domains). Geographically the city is divided into rings, spreading out from a central palace complex which is ruled by the Deva directly. The outer rings are reserved for humans, with the middle rings being the domains of the various castes. The central part of the city contains not just the palace and temples but also a port for sky chariots (fllying machines) and an oracle well. There are also gladiatorial arenas, and the local champion is a huge man with many scars.
The city is surrounded by estates maintained by slaves, and by lightning pikes that work to capture lightning for weird generators.
Egypt is the domain of Horus but is ruled by a human representative. The country is recovering from Sekhmet's rampage. The area is the place where the Deva first touched down and it has a special significance. Recently a game between the two Deva houses that ruled the area spiralled out of control and led not just to conflict between the humans but the Deva themselves. It led to the destruction of the House of Set (after the assassination of Osiris) and added free humans to the world as the livestock held by the house fled into areas that are less controlled. While Horus has established control over the region but problems persist. The General of Set's forces is among those that fled, and he is gathering an army.
Deva: Tall and beautiful, the Deva are the masters of Earth. They are the architects of everything that they consider makes the planet worth anything at all. They are divided into houses and lineages and have, over the centuries, become the image of the fat, absentee landlord. They largely govern through human proxies, relying upon cults, mystery religions and priests to maintain their power as they devote themselves to increasingly esoteric pleasures. War has become an amusement for them, even when it ends in disaster (as it did with the fall of the House of Set, a war that destroyed one of the Deva's houses almost entirely and allowed much of the human livestock to escape south into Africa), as has developed ever more complex rituals and religions. A handful has rejected their heritage and adopted alternate lives as free agents, traders and pirates (but it might be that they are simply playing the system in their own way). These rebels often use technology that looks like human machinery to blend in, even though their devices are more advanced.
The longer they stay on Earth the more fragmented the Deva become. Their ruling council is starting to struggle to contain their squabbles, and these are starting to threaten to boil over into wars of a more dangerous variety than they are used to.
The beautiful faces they show to humans are a disguise, the Deva wear 'flesh suits' for such encounters, appearing human and beautiful; in reality, they resemble octopuses. They maintain additional bodies to wear.
Culturally the Deva value order, accomplishment and hierarchy, they attain a role at adulthood and are expected to adhere to it for most of their lives, staying within their structure for their own good. They may be permitted to advance up the pyramid but it's a hard and arduous struggle to receive recognition for their work. Falling back down the pyramid, in contrast, is easy.
On Earth, their main stronghold is the city of Atlantis (set on what will become Cuba) and this is about the only metropolitan area they rule directly. They maintain certain strongholds in mountain fastnesses, where they maintain garrisons but little else. They also have cities at what will become Malta and in the caves under the Kurdish Mountains.
Their technology is focused on spaceships, sky chariots, suits of armour and weaponry, though they also have esoteric communication devices and 'gene locks' that prevent much of their technology from being used by humans or Raksha. Their genetic experiments are prompted by their technology and the fact that they are not allowed to undertake these tests at home.
Raksha: In their natural forms the Raksha resemble amorphous blobs covered in eyes and mouths. Most of their time is spent in a 'held' shape, often one that's bipedal or that balances a humanoid torso and head upon a long, serpent-like tail. They are a brutal race, any social niceties worn away by the long conflict with the Deva. The strongest rules and they determine strength through hunts, martial contests and shaping tests. Inhuman in their priorities they delight in hunting the strongest men and creatures and devouring them afterwards. They normally hunt in their humanoid forms, with only slight additions, claws, lashes and the like (it is considered 'wrong' for them to hunt and kill with separate weapons, the only weapons and tools they need are themselves).
The Raksha are naturally nocturnal and prefer underground lairs, inhabiting caves for the most part. This has allowed them to take control of some human settlements, replacing their leaders and making them more antagonistic to the Deva.
Humanity: Divided into castes and classes humanity labours for their masters. Most people are slaves or operate in a system where freedom is a delicate thing that could be snatched away at any moment. The vast majority of people are simply labourers, miners and merchants or scribes (or follow other professions). They struggle and make do. Technologically their tools and transports are around the late Stone Age, early Bronze Age. Some 80% of humanity is in this situation.
The exceptions are the four Castes the Deva set above them.
The Giants are the first, created to build great palaces and eventually tombs. Standing at seven foot tall at their shortest, they are muscular paragons, but essentially stupid and easily controlled by the Deva.
Psykers have been elevated above the other parts of humanity, gifted with psychic powers. They serve as advisors, spies and priests to the Deva. It is common for them to be marked with scars and brands on their bodies, and especially their faces. There are four psychic disciplines: telepathy telekinesis, pyrokinesis and clairsentience.
Warriors/Soldiers have been raised to peek human physical standards and gifted with intricate knowledge of Deva weapons. They work to guard the Gods, rather than other humans and they wear armour that strips away their humanity. Some also fight in the arena, battling monstrous creatures created by the Deva geneticists.
Technicians are taught the intricacies of the Deva's machines and are bred for their scientific minds.
The Rebellion(s) include members of all four castes and general humanity. Led in Atlantis by an elderly woman who lost her children to the Deva, they use codes and cyphers to fight the aliens but are limited in what they can actually do. Most of their actions are directed at small targets, disrupting operations, killing lower down functionaries and so on. Slowly, they are planning bigger jobs, killing Deva themselves and even to hijack a sky chariot and storm heaven itself.
The Free Tribes exist outside the Deva's direct areas of control (which tend to run around the equator) and live hunter-gatherer lifestyles in the north, or have established kingdoms and empires of their own in the south. In the south, a General of the Warriors caste has defected and is gathering an army in order to drive the Deva out. To the north, a strange cult grows in honour of the Earth Mother, and their object of worship is a Deva geneticist who has grown to hate what her brothers and sisters are doing with her creations.
The other Deva work to conquer the Free Tribes, using cults and psychic weapons. For their part, the Free Tribes work at resisting mental domination through meditation. Like the Raksha, they value strength and use hunting in their rituals, often as a way of proving themselves fit to be adults.
The Hairy Men: Neanderthals, Sasquatches, Yeti. These men and women are the natural humanity that lived on earth before the Deva arrived. They grow increasingly rare as the other parts of humanity, and the aliens, hunt them down.
Threats and Monsters
Ghouls - a failed experiment in tomb guardianship, the ghouls escaped and began to plague the cities.
Shadow hounds - hunting dogs the Deva use (some of them have been replaced by Raksha
Manticores - created for the arena, but typically some have escaped.
Wendigo - a failed experiment turned loose to hunt the escapees.
Tomb Guardians - created to guard the tombs and palaces of the Deva.
Lizard and cat people - exotics made for the amusement of the Deva.
Gladiators fighting a manticore
Looking up into the sky to see sky chariots flying over the city while there's a pyramid's in the background.
A tribe clustered about a cave mouth and looking out at a Deva
A group of Raksha feasting on a dead man.
A crowd watching as a sky chariot descends from the sky.