Maxperson
Morkus from Orkus
Yes. We want the mechanics to be mixed, because genetics mix. We are okay with humans being cosmetic only, because WotC(rightly) wouldn't touch human subraces with a 1000 foot pole. If humans did have mechanically different subraces, we would want those mechanics to be mixed as well.The Turani/Shou is literally the same of @Mistwell 's Korean/African example. Human heritage in 5e has no mechanical representation. Any attempt to represent such a blending is 100% RP. And we're fine with that because we wouldn't DARE give human heritages any mechanical standing. It shows that we as players tolerate the concept of mixed ancestry being only aesthetic as long as there are no mechanical elements attached.
All of the mixed subraces of the same race have this issue. Hill Dwarf and Mountain Dwarf, Deep Gnome and Garden Gnome, etc.The high/Drow example shows a much better example. They are both elves and there should be no logical reason they can't interbreed. But the two types have mechanical differences. They are 75% the same traits, but the question comes on how you represent that remaining 25%.
You just mix the mechanics on a case by case basis. Work with your DM. RPGs do not have to figure out every possible circumstance and put it into the books. They can't do that.
This is how I would do a High Elf/Dark Elf mix. I'm using the 2014 versions, because I have a headache and don't want to look up the playtest versions.
The PC would get the stat bonus of the players choice. The Dex would be +2, and then player choice of +1 Int or +1 Cha. Drow have darkvision, but high elves don't. I'd give the PC darkvision of 120/2 which gives the PC 60 feet. Better than the high elf, but worse than a pure(for lack of a better term) drow. Sunlight sensitivity seem cultural, so that would only apply to the PC if raised by the Drow parent in the underdark. Since both get magic, I'd give the player a cantrip of his choice and then at 3rd the option to get faerie fire or dancing lights, and at 5th level faerie fire, a dancing lights or darkness, depending on the 3rd level choice. Elf weapon training would be a no unless raised by the High Elf parent as that is cultural. Same with Drow weapon training. Since there's no real power increase in that mix, I'd also just let the PC have the extra language. And done!
It wasn't hard to come up with an appropriate mix for those two subraces and I could do something similar for any mix of subraces from the same parent race. WotC doesn't have to worry about that and can just come up with rules for two different races interbreeding.
One does not lead to the other, because only one has mechanical differences. It's only bad for the elf/human mix, because not mixing the mechanics denies the mixing. If there were no mechanical differences between elf and human, then purely cosmetic mixing would be okay for them as well.Suffiice to say that if "pick an elf, re flavor it to half-elf/human" is bad and possibly offensive because it reduces the effect of the second parent to only aesthetics, then the Turani/Shou should be similarly bad (both parents are only aesthetics)
To be honest, I never really thought about how two different elven subraces would mix until you asked the question. It wasn't that I didn't care, but that it just didn't come up. I've never tried it as a player and none of my players have asked.And we let both of these corner cases ride because nobody cared until they removed half-bteed races from the game.
First, they won't be able to pick all of the best traits. If they did make such a system, the various traits would have to be given a weighting. weak = 1 point, moderate = 2 points, and strong = 3 points. Or something similar. A mixed race would be capped at the same total weighting of a single race. Picking all the best traits would be too costly.Which brings me to the only solutions. You either completely redesign the species system with an eye towards intermixing traits, most likely though a customization system (which, knowing most players, means pure blood species will never be used. Look at how the fixed backgrounds are already being rejected for customized ones. You really think a species mixing system isn't going to be similarly used to pick all the best traits?) or you make it purely aesthetic and just pick one set of stats.
Second, mix and match as you please or purely aesthetic is a False Dichotomy. I just provided a 3rd way to do it. And a fourth way to do it is not to let every single race intermix. Most species can't interbreed. Human/Elf and Human/Orc can be the two that can. Nothing wrong with saying that the two exceptions that have been in the game since the early days remain the only two. And I will bet that more ways can be figured out.