I've been thinking about some of those sci-fi series that feature humans as fish out of water, along with this thread elsewhere about humans being the most dangerous species in the universe. And I hit upon something I've mused on before, using Mass Effect's prehistory to build a setting from.

For me, using an established setting's past isn't a new idea, I often find it's much more conducive to playing games consistent with the themes espoused, or focusing on a particular premise, than using the present or future. Not least because there's often a timeline which tells you what's going on at the time.

In this instance, it's the reveal that the cache of Prothean artifacts on Mars were part of some sort of scientific monitoring station, the Empire was observing what early humanity was up to. Apparently the scientists there scrubbed their results before the Reapers destroyed them, to make sure they didn't harvest the Earth early. Anyway, none of that is relevant here, because it won't be set during their war against the machines.

The core of it is this: someone in the Empire's military comes up with a more interventionist project regarding Earth. Instead of merely observing the natives, they selectively "recruit" (ie abduct) humans for uplifting to current galactic standards (via sleep-teaching or some other appropriate tech), to serve in a special auxiliary unit (think janissaries or mamluks for historical analogues). That's the "experimental" option, assuming this is a relatively new practise that their piloting/proving. Alternatively, the Empire has been at this for a while, and they have an entire program where they fill auxiliary regiments with humans for their nastiest jobs.

From the humans perspective, there's a legend about champions being selected from those who can climb a particular mountain. All the PCs would start out as regular Neolithic types motivated to test that legend. The first session or two would establish them in their original lives and feature that challenge. Not as a bait-and-switch, the players would be in on the "secret", that the nature of the campaign will change not long after starting. When the recruitment bit happens, they get to remake their characters to fit their new horizons, which might include biotic ability if they've chosen something as a precursor for it. After all, there was eezo on Earth before the 23rd century.

This whole idea has precedent in the way the Council races uplifted the krogan to fight their wars - this is a spin on the same idea.

As to what the point is, there's a mixture of the elements that are familiar in the ME universe (since tech is ubiquitous by design) with the added novelty of featuring pretty much none of the races we're familiar with, or the Council. It's carte blanche to do whatever you like with the lay of the land, but seen from a human's perspective. You could twist the Prothean Empire however you like, they might simply be functionaries for the evil empire, or there could be a genuine ideal they're fighting for.

Looking for thoughts to develop this idea:

• Why might the Prothean Empire sign off on this idea, and what's in it for the project's leader?
• What are these human auxiliaries used for - cannon fodder in some particularly nasty war? Loyal shock troops in some sort of civil conflict where the Protheans can't trust any of their established allies? Seeking a new edge in a war that's ground to stalemate? Something else entirely?
• How weird do you make the Prothean Empire, and how evil for that matter?
• How much of the PCs original lives should feature in their uplifted selves? Would it be interesting for them to retain tribal affiliations and customs, for example?
• How long is appropriate to play out the "challenge" part before they're uplifted, or would it be better to just skip that and start them out as Prothean auxiliaries?