in the enhanced edition at least the primairy attributes seem to limit multiclassing (esp for warriors/man-at-arms that can only dip into the buff/summon groups of other skills). and the intelligence group is swamped with options because the game sports 5 magic schools. though attributes are a stable in RPGs, and I personally feel they should stay.
strength: carry capacity, power with any physical weapon that requires hitting, throwing pulling etc. capability to carry heavier armors and shields without impeding speed. fortifies resistances that dislodge the character like knockback or tripping.
dexterity: character accuracy and balance, power of any weapon where accuracy is key, this includes magic projectiles. ability to dodge and block attacks (reactions) critical hit rate. ability to craft small or fragile objects effectively, empowers lockpicking.
constitution: character stamina and body chemistry, affects AP max, start and recovery, HP total and recovery deals with resistances that directly attack the body like intoxication, poison, disease, stun.
intelligence: character logic and comprehension, should affect available skill slots for any school, crafting, incantation strength of spells and resistance against spells that affect mental aptitude like charm, confusion and fear.
speed: characters movement speed, initiative and action point recovery.
perception: strength of the characters senses, counteracts blind and enemy invisibility, allows spotting of secrets, traps and tracks. increases stealth.
now naturally this has to work hand in hand with the equipment system and other skills, having strength to allow characters to work better in heavy armor should means that mages bathrobes should not have a equal level of armor. most weapons should get scalings in both dex and strength, leaning more to strength for greatswords/axes/warhammers and more to dex for spears, rapiers, daggers, and bows...but both will be needed to get the best out of the weapon while for elemental stuff, int comes into play as well. int also comes into play if you want to do more then just "hit stuff with the business end"
I would also tie a great deal of the bodybuilding and willpower skills into the main attributes and equipment given resistances.
