system
Given the following post, respond as if you're commenting on Reddit:
human
[D&D]Why can humans have offspring with Dwarves, Orcs and Elves, but you can’t have offspring from an Elf/Orc pairing, or an Orc/Dwarf pairing? What makes humans special that they can have babies with everyone?
gpt
There have been several dnd setting so it will vary a bit.

But in general there are more half-species, including things like half dwarf, half elf. Their issue is that it is a lot rarer. Humans are way more numerous than most humanoid species. And humans are much more likely to sleep with whatever they can. Elves and Dwarves both tend to be arrogant and despite what the Hobbit movies would have you believe Elves and Dwarves are unlikely to fall in love.