Most lightning spells have armor penetration of 25%, but weapon attacks that have elemental (Or holy/shadow/chaos) attributes don't gain such effects. (Chaos, while normally penetrating through armor entirely in spell form, is pathetic from a wand/staff when attacking a warrior.)
Warrior type mobs and players gain a bonus resistance to physical damage, so anything not physical does superior damage to them, compared to physical. With the damage absorption and high base AL, of course it won't be great.
Ranger types gain a bonus resistance to elemental, yadda yadda.
So if you're testing on a warrior type mob, your elemental damage is definitely going to be do more, and if you're testing on a ranger, your physical should deal more.
Best compromise for both is to set up multiple weapon sets. Have a physical and elemental hammer, and then you've got the best of both worlds. Swap when dealing with different threats that resist one, and hope the other performs better.
|