Deflect
by Craig AntounI believe it only means opponents attacking with hand-held weapons and thrown weapons if it the Primary Target for the weapon is H.
If the Primary Target of the deflecting weapon is M (creatures attacking with missile-fire or natural weaponry) or A (all types of targets, both H and M), then the weapon can deflect natural monster attacks and missile fire.
The club has Primary Target of M, and has the deflect ability, so by the rules it should be able to deflect claws, bites, and whatnot from monsters, as well as deflect missile fire. The staff has Primary Target of A, and can also deflect, so it can deflect all of the H and M type attacks.
I have always also limited the Special Effect of weapons to only the Primary Target of the weapon. It never made sense to me that you could use the Special Effect of Deflecting with a sword (Primary Target of H) against a monsters natural melee attack.
I have found that the Deflect ability based on a Saving Throw vs. Death Ray is way too unbalanced. It is far to easy to make this saving throw at higher levels. So I use this alternate house rule:
Deflect
To deflect an attack that has struck, the target must make an opposing attack roll. If he hits the same or better armor class than the attacker did, he has successfully deflected the attack. If the opposing attack roll fails to hit the same or better armor class that the attacker rolled, then the deflect fails and the attacker may roll damage. Deflect may be used against hand-to-hand and thrown missile attacks.
I also like your suggestion about the attacks of very large monsters not being able to be deflected. I think that makes very good sense.