ALWAYS, and believe me, I mean ALWAYS, save your game and keep a backup before you start on any of the promotion quest dialogues. You get one chance at these and one only, so if you get it wrong, you're screwed.     The way to find out is, after the promo dialogue is over, you press Z to see if your player has been accepted as a candidate for the promotion that he/she wants. If not, reload your position and start again. You can do most of the other promo quests and get the experience for them, but if you really want to promote your character, check that he/she has been accepted for the rank. Once he's been accepted, you can save over that position, but keep it until then.

There is one exception to this, and that is the lich promotion. Liches are arrogant, solitary people who acknowledge no superiors, so if you want a character to become a lich, he/she does it all himself or herself. No notice of a scholar's candidacy for the rank of lich will ever appear in the character summary when you press Z.