The much-maligned "Save Or Die" mechanic could use a facelift. In old-school Dungeons and Dragons, your saving throws are disassociated from your character attributes, instead connected to your class. This results in extra record-keeping, as at the time of character creation you must consult a special saving throw table and record your saving throws, and then reference that table each time you level, to see if your saving throw scores have changed. It seems to me that if saving throws are tied to classes, and each class has a prime attribute, that it would be much simpler to connect the saving throws to attributes instead.
I'm sure the idea of connecting saving throws to character attributes is not a new one. Here is an optional saving throw system, which I found in an old binder of mine. I can't take credit for this system, as I don't recall developing it.
SAVING THROWS
Your saving throw versus a particular threat is based on the attribute related to that threat (see below), modified by your level. In order to pass a saving throw, roll either a d20 or 3d6 (whichever is the agreed-upon method) and subtract your level. If your dice roll, modified by the subtraction of your level, is LESS than your attribute, you pass the saving throw.
Strength: save versus paralysis and constriction
Dexterity: save versus breath weapons, gaze attacks and traps
Constitution: save versus disease, energy drain and poison
Intelligence: save versus magic and illusion
Wisdom: save versus demon/devil/divine magic, confusion, polymorph/pertrification
Charisma: save versus death attacks, charm and fear