Whenever I work on a game I like to take some time in pre-production to think about what goes into it.

Jupiter Sovereign is just a sketch for me, but I still want to do it right. As a result I'm going to need to move very quickly through key points and not get too caught up in details.

History of the Setting

So the Jupiter Sovereign universe will be set in a sort of dystopian transhuman future. It's inspired by alchemy to a degree, but there's also a goal of having a universe that's meaningful and interesting, without being strictly tied to symbolic purpose.

I'm also not really great at astronomy, and a lot of what happens in the universe is powered by handwaves. Getting it right would take longer than I have. All maps are done without any attempt at scale.

The two maps I'm including with this are not necessarily final, but show some of the elements of the setting.

The Sol System

Backstory

The idea for the Sol system is that it's our world, but maybe five hundred or so years after the current day. There have been some minor changes; Sol has been colonized using a megastructure (a partial Dyson sphere). During the colonization of Sol, one of the workers discovered an artifact from unknown times. The artifact eventually came to be known as a Philosopher's Stone, and it enabled the First Alchemist to unlock tremendous capabilities, later codified as psionics.

Psionics is the art of turning the psychic reality into physical reality. With the assistance of the Philosopher's Stone, twelve distinct disciplines have been unlocked. Humanity is inherently capable of unlocking psionic potential, but it requires training and equipment that we had not been aware of prior to the discovery of the Philosopher's Stone.
– Adomas, First Alchemist

Following the discovery of the Philosopher's Stone, the sky was the limit. Not only was travel within the solar system cut down to nearly instantaneous timeframes (the transfer of minds as data made this less significant, but still important as a way to transfer tangible substances), but the First Alchemist's academy on Jupiter turned out wonders of science that defied traditional understandings of the universe.

The decade that followed was exceptional. While humanity never formed a perfect union across the entire system, the various wars and conflicts over resources burned out as psionics enabled plenty and prosperity.

Then the First Alchemist disappeared. Jupiter, already a superpower due to its role as the center of psionic studies, created colonies among distant stars. Kronos, Ouranos, and Cupid were founded around a binary solar system, the first human extrasolar colonies. Earth colonized another system, building the Vulcan, Poseidon, and Proserpina colonies.

Exolife on these planets led to the discovery of new potentials, and the Gigantes were created; machines that can amplify the power of a psion.

However, the psionic boom was found to have a cost. With the First Alchemist's disappearance, the Philosopher's Stone was no longer present to amplify the potential of humanity. A cold war began as Jupiter sought to create spirit AI that could replace the role of individual psions, whose powers were limited by their own experiences.

The creation of a new Philosopher's Stone was posited, but with no known coalitions of psions who had the mutual capability to complete the process, a stalemate ensued. Asad Zaman, a researcher on Earth created the first successful prototype. Incapable of accessing more than one domain of psionics, the artificial lifeform still represented an opportunity: creating one for each of the twelve domains would be enough to unlock the secrets of a Philosopher's Stone.

Crisis

After several years of unsuccessful research, the attempts to create more spirit AI in other domains were ended and treaties were established to prohibit their development. While spirit AI themselves are not forbidden throughout the sphere of humanity, the creation of new AI is: forbidden AI are referred to as "demons" in propaganda.

Zaman continued his work in secret, but when his actions were uncovered, Zaman was imprisoned in Earth's colonies on Proserpina.

Conflicts over limited resources resume as psionic potentials run dry. With the wane in power, only a small percentage of the population are still capable of accessing their abilities, and only with the assistance of amplifier devices, which require rare transuranic elements.

Wars break out across the system as the planetary governments balkanize. The colonies are largely untouched; their lines of supply limited by the number of FTL vessels used in the conflict and the increased difficulty of operating the drives that power the ships outside of the influence of an amplifier (before the First Alchemist's disappearance, the return trip from the colonies consumed so many resources that vessels were often sent one-way, and only data was returned to Sol).

With balkanization comes the increased production of Gigantes. Any competent psion could activate a Gigas (such users are referred to colloquially as alchemists). Due to their larger size, the psionic focuses in a Gigas could be used without requiring the same rare (and quickly decaying) elements used in personal psionic focuses, so the Gigantes became the preferred way of augmenting a psion's powers.

Many Gigantes are deployed in the first years of the war, and a general humanoid form becomes the preferred method: this enabled better use by unskilled pilots and permitted distinct focuses to be compartmentalized within the limbs of the Gigas, preventing interference between them.

Then, ships from the colonies arrive.

Zaman's War

In a matter of hours, a fleet of vessels arrives from Proserpina. Earth, unaware that its colony had been taken over by Zaman's agents, was obliterated in psionic fury. Zaman's manifesto was rambling and incoherent, the work of a man who had been tortured in captivity. Channeling his rage, he destroyed his homeworld in an instant, and billions died in the next few hours.

The war was brief, lasting mere days. Seeing the destruction wrought on Earth, the inhabitants of the Sol system put aside their differences, and retaliated firecely. Zaman had created a second Philosopher's Stone, and the power it gave off was sufficient to amplify the already stretched psionic capabilities of the alchemists.

Zaman pushed the Philosopher's Stone to the limit in an effort to destroy as much of the solar system as he could, but it failed him. As suddenly as it had been created, it disappeared. There is no academic consensus on whether this was a consequence of flaws in its creation or that Zaman had simply pushed the Stone past what it could bear.

From the remnants of Earth rose a psionic entity. This Demiurge placed a sphere around the inner planets, the Great Barrier. For months it indiscriminately attacked anything it encountered; Zaman's fleet was destroyed. Luna was spared for reasons yet unknown, but the combined Solar fleet was also decimated by the Demiurge.

The Demiurge left darkness and destruction in its wake. The survivors of its manifestation, the Exiles, were changed and haunted by their experiences. Their own psionic abilities ruptured, any psions who had survived the destruction of Earth in shelters or orbital colonies found themselves corrupted; their bodies warped and their minds shattered.

The Demiurge continued its rampage. Ignoring planetary settlements, it assailed the asteroid colonies and spacefarers unfortunate enough to be caught outside the protection of a world.

The Demiurge expanded its presence to the Colonies as well, though the fact that their population was largely limited to terrestrial settlements reduced the damage it could cause there.

Renaissance

The third Philosopher's Stone was created to fight the Demiurge. Jupiter coordinated the efforts, hoping to reclaim its interstellar empire, but it was on Sol that an ascetic order managed to transcend their human limits and bring about the third Philosopher's Stone.

The Order of Helios used its Philosopher's Stone to crack the Great Barrier. Behind it laid only destruction: the aftermath of a supernova. They turned their efforts toward the Demiurge, containing it in the Golden Prison, a structure underneath the surface of Sol.

Then they, like the First Alchemist, they disappeared. The Exiles were re-integrated into humanity, and the healing process began. Jupiter rebuilt its navy, preparing for an assault to reclaim its former territory. The Colonies remained unaware of developments at home, though the Demiurge ceased harassing them and trade between each of the colonies resumed.

Despite looming stormclouds, Jupiter reigns sovereign.