Some generalities:
- The setting would be our own Milky Way, in “the 33rd century A.E.”, some 25,000 years into the future.
- The Galactic Republic/Empire would span a million worlds, with the entire known galaxy in toto spanning 25% of the Milky Way.
- Though not particularly speciesist, the Galactic Republic would be an almost entirely human/near-human domain. There’d be very few member worlds with significant non-human populations, and human/non-human admixture would be almost unheard of outside the Outer Rim territories.
- Strong AI wouldn’t exist. Droids such as Artoo & Threepio would be cyborgs — robot bodies controlled by cultured organic brains.
- There wouldn’t be manned fightercraft, but remote-controlled/robot fighters. Remote-controlled fighters would have some advantage over robots, as organic pilots can outwit the weak AI of robot fighters. However, in the event of remote-controlled fighters receiving heavy damage, feedback through the neural interface would kill/brain-damage organic controllers.
- Lightsabers would be entirely mystical, non-technological weapons which could only be constructed/ignited by trained Force adepts. At the heart of every lightsaber would be a kyber crystal, its colour shaped by the psyche/preferences of the adept who meditated over it. The lightsaber blade would be paper-thin with monomolecular edges, capable of cutting through almost any material by severing covalent bonds.
- Force-sensitivity wouldn’t be genetic; it wouldn’t be inherited patrilineally, and clones of Force-sensitives wouldn’t inherit their template’s Force-sensitivity. However, Force-sensitivity would often pass on matrilineally, and if one child in a set of twins is Force-sensitive, their sibling(s) would invariably be Force-sensitive as well.
- All space flight/space combat would be three-dimensional.
- Single-biome worlds capable of supporting complex life would be rare/marginally habitable. Life on Hoth would be limited to the equator, life on Tatooine to the poles, etc.
- Hyperspace travel would be relatively slow. Travel between Tatooine and Alderaan (both Outer Rim planets) would take five days along a good hyperlane.
I’ll go into more plot/character-specific details later.