Praise then darkness, and creation unfinished

I've been reading Worlds Without Number recently and of course, as I do with basically every gritty fantasy setting that I find, I think, "Oh, I should convert the mechanics over to Exalted 2e! This is a game where an ambush could take out even a well-equipped but unprepared party, where every spell is a puissant working, and where bizarre monsters and hostile creatures abound! Perfect for Exalted." It works for years for Warlords of the Mushroom Kingdom.

Anyway, this isn't as much about that, it's about the way Worlds Without Number does fantasy races. The default setting is Dying Earth, so far in the future that all records of the past have been totally lost--the book drops hints that it's the same continuity as Stars Without Number, the sci fi game from the same company, but enough time has passed that the star-spanning Terran Mandate is no longer remembered even in legend. Humanity was confined to the homeworld and ruled by capricious aliens collectively called Outsiders), who placed most humans in subterranean "Deeps"--the worldbuilding excuse to have dungeons to adventure in--and experimented on others. Fantasy races, then, are the descendant of these experiments.

Worlds Without Number then does all the traditional fantasy and sci fi niches with these. Dwarves are humans adapted to underground Deep living and with a deep psychological commitment to a particular ideal they call their "Plan"--I assume the author has borrowed this from Dark Sun dwarves' Focus. Elves are self-reincarnating immortals, who are reborn as another elf when they die and in extreme circumstances can commit identity-suicide and call on a mighty warrior or powerful archmage prior incarnation to slaughter their enemies. And orcs are the "Anakim," warriors engineered by the Outsiders to kill as many humans as they can.

It's obvious that the game is going for orcs that you can kill on sight without any moral questions, and so the background is that the Anakim were engineered with what they call "the Hate", an instinctive and overpowering revulsion and disgust response when in the presence of baseline humanity (and human-similar demihumans). Couple this with reduced inhibition and increased aggression, and it means that Anakim react to nearby humans with unprovoked brutal violence. Peace isn't possible because only the strongest-willed Anak can even be in the same room as a human without immediately trying to murder them. The only reason they aren't a larger threat than they are is because all of that poor impulse control and violence means that Anak society is a patchwork of squabbling tribes led by the strongest and most violent leader whose leadership only lasts so long as the rest of the tribe is afraid of them. Warlords who can manage to unite multiple tribes are rare and have to lead the Anakim against the hated humans before one of their underlings pulls them down.

The book does say that there's a certain kind of player who, when confronted with this, will make it their goal to cure the genetic engineering in the various "Blighted" species, like the Anakim or the Houris (who are beautiful and graceful and never suffer from old age but experience immense contentment and satisfaction from obeying orders, no matter content or issuer of the order) or the Zakathi (who are immensely strong but need to completely exhaust themselves with physical labor every day or wither away and so usually die in their 50s when their bodies give out). And it is possible--one group of Anakim slaughtered their Outsider overlords, stole their tech, and managed to modify their psychology using it and selective breeding so the Hate is expressed as contempt against the unruly humans and their aggression is all social status-jockeying rather than an axe to the face. These Anakim call themselves the "Aristoi" and think they're better than humans. Maybe your PCs could do the same thing! They can certainly try.

I really like this approach because it sidesteps most of the questions players ask about always-evil orcs--they weren't created by the gods and they aren't naturally evil, they were created as an anti-human weapon by asshole aliens and they used to be human--and provides an epic goal for players who are bothered by this. And if they're not bothered by it, they can just attack first because almost every Anak they see will attack on sight with no quarter asked or given. And it explicitly says some Anakim do have the willpower to resist the Hate, so there's room for backchannel dealings, accompanying a merchant clandestinely dealing with some Anak warlord looking for an edge against other tribes, etc. That's excellent worldbuilding that is directly applicable at the table, and we can always use more of that.