ToME: the Tales of Maj'Eyal

Did you already close the window where you assigned the category point?

If not: Just remove it the same way you would remove a skill or stat point.
If yes: Not 100% sure, but it doesn't seem like category points can be reassigned as they change your character permanently.

So my first ever character who has a human arcane blade died a horrible death in the maze while i was trying to learn the rules for the game. Then i made a Shalore alchemist and things went a lot better this time around. I have not managed to kill myself yet. I was just scrolling through GoG looking...