STR, DEX and INT during character creation
IMPORTANT ! Skills and their associated physical trait MUST add up to 100 at most. 50 STR + 50 Barehanded fighting = 100% chances of success.
If you go over 100, you can get critical failure, and in the 128-255 range you simply bug the game and corrupt your save ( signed byte problem, 128 = -127 )
So if you want to raise a trait ( for better encumbrance for example ) you'll have to lower the related skills accordingly.
If you're not sure about what I'm saying, just put 50 in both Traits and Skills :)