Been thinking about the Fermi Paradox in fictional universes with FTL travel and lots of aliens. On the one hand, the Fermi Paradox has been solved and the answer to "where is everybody?" has been answered. But on the other hand it begs the question "why isn't the universe a monoculture of the first species to achieve FTL?". Evidently, interstellar civilisations in these universes do something or encounter something that gets them ganked.
Earth is not a monoculture of the first culture to achieve transoceanic travel
It's a classic, but if you haven't read it:
waitbutwhy.com - The Fermi Paradox - Wait But Why
Best blogger ever
I think an answer, analogous to the aforementioned comparison with transoceanic travels in Earth, would be that there is no overwhelmingly dominating culture across the Galaxy because by the time the first civilization develops FTL and start exploring there are at least a handful or a dozen other civilizations reaching a level of technology not too dissimilar, so encounters between civs are not rare to happen between more or less "peers" (as in, a civ with FTL and another one in the equivalent of Stone Age).
This of cours begs the question as to how this could happen, since the chance that even two civs happen to roughly arrive at more or less the same tech level in about the same time period of a century or two (more than that could be too late for the less advanced to resist the massive cultural absorption) is very small - more so if we require a dozen of them to happen.
So there has to be something that kickstarted all these civs at about the same time in the past and overlooked for deviations to the plan.
Another fun(?) alternative could be like this short story:
Humans were on the verge of winning the Fermi race, then the scream happened. Humans still out number aliens within the borders of the old mandate.
provides a viable answer: all but a handful of alien species stay in their home system, disappear into other civilizations, and/or die out. Humans are on top in the 30th century, but in a few hundred thousand years they might be the vanished elder civilization to some new upstarts.
Granted, I prefer all characters, especially PCs, to be either "classic" humans or genetically engineered or artificially augmented variations. Too often "aliens" in fiction (and RPGs) end up as humans with bumpy forehead and one extreme character trait.
Truedat. That's why I try to mix up my "bumpy forehead" aliens with truly bizarre aliens from, for example, Silent Legions.