Out of curiousity, in your home campaign do you know of any half-dwarves or half-halflings (quarterlings?). We know humans and elves can tango, and humans and orcs. Why not dwarf/halfling, human dwarf, human halfling and such?Certainly. This has come up a lot over the years, and my answer remains the same: such individuals tend to favour/"pass" for one parent race or the other…and out of social convenience, almost invariably choose to "blend in" (e.g. a tall human/dwarf w/humans).#Realmslore
— Ed Greenwood (@TheEdVerse) November 19, 2021
This was one of many design choices to make the Realms fit the official D&D rules of the time.
Gary Gygax had in The Dragon made it clear most races could have offspring together, but the game lacked a lot of half-race rules because such individuals were so rare; FR had to match.— Ed Greenwood (@TheEdVerse) November 20, 2021