Here's my dualling experience with my fighter/mage, Kayla that validates Kittu's reply. I started her out a a fighter and made sure she had 18's for STR, DEX, INT and CON. For her beginning 4 points of proficiency I gave 2* in missile weapons (as I wanted her to *eventually* use a shield, she had to use a sling as a missile weapon), one in daggers and one more for mace (to deal with skeletal undead).
When she levelled up as a L3 fighter, I gave her a proficiency in another weapon (can't remember which, my memory is getting baaaaaddddd
) then immediately dualled her to mage - and lost ALL my prof points.
I had one single point to spend, which I put in missile weapons. So she was stuck with just one point in missile weapons until she levelled up as a level 4 mage, at which point she got her fighter abilities back - only this time the point I had put into missile weapons as a mage had disappeared!
So in total, I had spent 3 points in missile weapons, but now she only has 2 stars in it.
Oh well, she just levelled up as a level 6 mage and got one more point to spend - which I stuck into longswords - there are some cool "large swords" I have discovered so far. Not that she needs it, her role is to stay back and hit monsters with whatever spells she has, and use her sling to. But you never know when you're gonna get ambushed, right?
[This message has been edited by Hayashi (edited 10-29-2001).]