So by that same logic, if a human is in the nine hells, does that mean they get the Fiend classification?
— Skull Dixon (he/him) (@SkullDixon) January 28, 2020
Visiting the Nine Hells in D&D doesn't turn you into a fiend, but that plane of existence might influence you to turn evil. For more information on how that infernal realm works, see "The Nine Hells" section in the DUNGEON MASTER'S GUIDE (p. 64). #DnD https://t.co/jPFjezolCF
— Jeremy Crawford (@JeremyECrawford) January 28, 2020
In the D&D multiverse, many of the planes of existence can affect you in strange and wondrous ways. Take a look at chapter 2, "Creating a Multiverse," in the DUNGEON MASTER'S GUIDE for details. #DnD
— Jeremy Crawford (@JeremyECrawford) January 28, 2020