How does Elem Adept feat affect spells cast on objects? Do objects have Resistance & Immunity? Fire vs. Stoneup to the DM, but I'd say it makes sense. We don't try to provide canonical definitions for objects in the game #wotcstaff
— Mike Mearls (@mikemearls) June 13, 2017
PC with Burning Hands & Fireball thinks that they burn most objects because Elem Adept ignores Resistance. I plan to rule Stone has Immunity Take a look at the "Objects" section in the Dungeon Master's Guide (p. 246).
— Jeremy Crawford (@JeremyECrawford) June 14, 2017