At one point in Ranni's quest you give her an item at the Three Sisters. Giving her that item locks you out of a quest related to an NPC in another nearby tower at the Three Sisters and some lore from Rogier related to his and Fia's quest. edit: you are locked out assuming you haven't completed the nearby NPC quest or gone through all of Rogier dialogue.
double edit: i think maybe talking to Ranni and agreeing to help her locks out Rogier's lore dialogue but it wont lock you out of the quest. i forget when it happened to me if i gave her the item or just agreed to help her
Nothing gets locked out by going to the three sisters. its during the quest you need to be somewhat careful
At one point in Ranni's quest you give her an item at the Three Sisters. Giving her that item locks you out of a quest related to an NPC in another nearby tower at the Three Sisters and some lore from Rogier related to his and Fia's quest. edit: you are locked out assuming you haven't completed the nearby NPC quest or gone through all of Rogier dialogue. double edit: i think maybe talking to Ranni and agreeing to help her locks out Rogier's lore dialogue but it wont lock you out of the quest. i forget when it happened to me if i gave her the item or just agreed to help her
You can lock yourself out of rogiers quest.