Let's say Alice & Bob have just completed a quest (see combat example), and have each been granted 50 XP.
They may spend their XP on upgrades to attributes, skills, or spells, at the following costs:
So what will our intrepid adventurers spend their XP on?
Alice decide to beef up her Knife skill. It was originally at 14, so she can spend the 50XP to improve it 5 levels to 19. Very decent!
Bob wants to invest his 50XP into some more spells. However, his GM informs him that he cannot learn new spells unless he finds a way in-game to get the information. Bob convinces Alice that they must go look for an accomplished mage right away. For now though, Bob upgrades his Heal Injury spell. It is normally Difficulty 10 so Bob spends 9 XP to bring the difficulty down to 1. This will greatly increase his success rate when attempting to cast this spell. He decides to hang on to the remaining 41 XP and save it until he finds an elusive mage to learn from.