Spell Resistance on player characters is virtually meaningless, it protects against almost nothing that isn't either A) has an easily acquirable blanket immunity or B) is a minor nuisance.
Spell Resistance on monsters only works against inta-kills and CC, giving an unfair advantage to nukers.
So I propose that Spell Resistance should work on damage spells too, mitigating 5% per point.
By this I mean that if a caster fails his roll against SR, each 1 point he fails by 5% of the spell damage is reduced (before any other mitigation).
So if a caster throws a fireball on a monster, the caster has spell penetration of 20 and rolls an 11, for a total of 31 against spell resistance, and the monster has 40 spell resistance, 40-31=9, 9*5%=45%, 45% of the damage is mitigated. If the fireball was going to do 300 damage, it instead deals only 165 damage. (300*(1-0.45))
This will mean that having Spell Resistance on a player will mean a chance to take less damage from spells, and make spell penetration important for nukers(sorcs/fvs) (that are op anyway).
Items with spell penetration will have actual value rather than being vendor garbage.
Thoughts?