Potential scenario idea:
Sol start
Conventional Tech
5K or less ground forces with conventional (1-4) weapons/armour - Preferably in small units
Pop of between 100m and 1,000m
No space yards or orbital industry, no maintenance facilities, nor anything else that could be considering 'all tech' or starting TN tech buildings
1-5 labs
Have conventional industry for between 1 and 7 billion - more than you've got pop for
Low survey, research and terraform speed with limited research admin on
Minerals can be whatever you feel like
Additional options:
Possibly (likely needs DB editing) create a conventional tech ruin on Earth linked to your species - if you can do this, replace some of the CI with it, the bigger the ruin, the more CI replaced
Create one small (sub 10m) pop outpost on Mars, this has to be the same species, not necessarily faction. They can have 500-2500t of infantry - preferably small groups
Create between 0 and 4 NPR factions on Mars, all 0 pop, multiple small infantry only ground forces
Create an NPR (or use one from the Mars militaries) and make an ark station over Earth, give control to either your group or a same race NPR
Create several infantry only NPR groups on Earth, one of these can be an offshoot of one of the Mars NPRs
If possible, create a set of ruins on Mars, Phobos and Demios for a second Mars NPR and add some infantry to the moons
Set up 1 or 2 of the Mars NPRs (of the same species) on another system somewhere away from Earth, this is where their pop is. It should not be the one linked to the ruins. If possible you could make one NPR be purely the military, without any pop at all, but it's the same species as another NPR
Set up the remaining Mars NPR in another system, again with a pop.
Description:
Towards the end of the 20th century or early into the 21st, Earth was attacked by aliens. Unlike most might think, they did not attack with explosive WMDs or high radiation weapons, but rather chemical and biological attacks. Most of humanity died to the spores, though some managed to make it to old nuclear shelters that had air filtration and waited it out. On returning to the surface months or years later, however, they found it a hostile environment thanks to roving bands of mutants that seem to be mostly former humans, although there are other things, including living hives and giant hermit crabs.
Now humanity's task is to pick up the pieces, find out who attacked and find out what else is hiding in the dark.
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If you're not sure what the scenario is, there was an X-Com knock off in the 90s or 00s called UFO Aftermath. Basically 'greys' attacked Earth to turn it into a giant biocomputer, except the project failed. For one, the mutants likely screwed things around, for two the group you play fought back. Canon route (Aftershock) involves most of Earth's better survivors being either taken to an arc ship turned station, which eventually gets destroyed and a small crew takes over the other, only to have to fight to reclaim Earth from mutants and aliens, and fanatics, with the aid of survivors and a couple of human variants (cyborgs and psionics). Meanwhile the rest were set up on Mars (Afterlight) and try to terraform the place, only to encounter more of the greys and robots belonging to another race before a warp gate opens to bring another threat through.
