Someone has probably mentioned this, but I've encountered a pretty bad bug on more than one occasion where the game will completely lock up (requiring forced shutdown in task manager) in the middle of a conversation after a dice roll. This has happened in conversations that popped up with Shadowheart in the Temple of Selune, and Astarion when you find the boar carcass. Somewhere on the interwebz I saw someone say that this happens if you are controlling a companion character when the conversation starts (but obviously not in every conversation).
