The refugees from Elturel are indeed a special case, we'll get into them, but first, background:
Tieflings first appeared in 2e, the the Planescape Campaign Setting, as two of the main new "planetouched" races (the second being Aasimar).
in 2e, and 3e, They are literally just part-fiends (devils and demons are fiends, but there are more than just them). Cambions and Alu-fiends are both forms of half-fiends, but if a half-fiend has a baby with a human, it'll most likely be a Tiefling. Fiend blood at 1\4 or less = Tiefling. Di'Terlizzi style Tieflings like Doric were the norm, and they were described as being mostly human, but with a few fiendish appearance traits, and the roll table for those different traits was MASSIVE. The reason Doric was most likely abandoned, is that back then it was possible for the fiend blood to become very diluted over time, to the point were people might not even know they had fiend blood, and then suddenly, oops! Tiefling baby! Looks like one of you had an ancestor who dallied with fiends. I've used that exact orphan plot for a character in a past game.
In 4e and beyond the lore was shaken up, as we had a number of realm-events that caused bug changes. In reality, this was WOtC homogenising a lot of Tiefling lore, and trying to make them a "true" race, despite them already being massively beloved by large numbers of the player base. Short story: Asmodeus became a god and as his first act, made all tieflings his direct blood descendants, and changed the rules for how Tiefling babies happen (no more diluted fiend blood). This came with a huge appearance change for Tieflings into something more like what 5e has, but with even less options. This kind of homgenisation was not taken well by fans.
Now 5e happens, and Tieflings are in the PHB as a standard race again, just like 4e, and just like 4e, they have the same standard appearance. But, fans were absolutely not using their standard appearances and just making Tieflings however they wanted. WotC attempted to walk back the homogneisation of Tielfings using some of their side books, where they gave options for different Tiefling appearances and racial attributes, but it wasn't until Mordenkainen's Tome of Foes that they gave us the separate bloodlines, which once again indicated that Tieflings weren't just one bloodline under Asmodeus.
NOW, the refugees. There is such a thing as "spontaneous planetouched", where a planetouched person could be created, but instead of being a descendant of a planar, they have been changed by the energy of a plane. This can both change an already living person from what they were into a planetouched, and also make any children they have be born as planetouched. With the fall of Elturel into Avernus, I imagine that both happened, people being changed, and also later, humans giving birth to Tiefling babies. Traveling to a hard-aligned plane like Avernus might have also changed people's alignments temporarily, so they would have acted like different people until they left. Planar travel is dangerous, things can happen to you.
Last edited by Piff; 19/10/23 11:03 PM.
