A terrible shame "The Thing"(Based on the amazing John Carpenter movie) and "The Chronicles of Riddick: Attack on Butcher Bay"
OG Xbox discs won't play in my Xbox One X. My brother game me brand new ones sealed and I cracked them open, hoping I'd
be able to play them on my One X through backwards compatibility but yeah...not happening. Sucks man.
To be more specific the game code is left untouched (except for Final Fantasy XIII trilogy where they used the PS3 textures), but the excutable file that the Xbox One uses to launch the game is new. The emulator comes packaged with the game itself, specifically fine tuned so that the game can utilise the Xbox hardware properly.
Apart from that, unlike OG Xbox and 360, the games for Xbox One and Series S|X are region free. So you can insert say the disc for Gernman or Japanese version of a 360 game and download the English version of the same game.