Quote Originally Posted by slopesandsam View Post
Wait, does Duncan even appear in the first book? It's been a while since I read it, but I feel like he was "Sir Not Appearing In This Book", oft mentioned but never actually there. He didn't show up until Dune Messiah.

Momoa in a bit part in the first movie makes sense, but if they wanted to continue with later books he's a weird choice to carry the entire series, given how important Duncan becomes.
Without providing too many details, lest I spoil anything for those who haven’t read or seen any of the adaptations, Duncan is most definitely in the original Dune. Check out the Wikipedia synopsis for further details, but that character does appear in the original.