Because by default you do 100% damage, resulting in an extra +1. % phys damage listed is the BONUS damage you get.
If you have a sword that deals 50 phys damage and 0 %physical damage, it deals 50 damage. 1 + 0 / 100 = 1
In your formula, it would be 0.
If you have 100% bonus phys damage, the sword deals 100 damage. In your formula, it would be 50.
By default, armour has a 70% absorption rate, which means that if you have 1000 armour, 700 points of damage is subtracted. That’s where the + (armour * 0.3) comes from, but conceptually I think it’s easier to understand if you do wd - armour * 0.7
It used to be that monsters had more absorb at higher difficulties but I believe that no longer applies. The player still can and should get higher absorb, though.
Either way, I’m assuming that the 650 armour figure was meant to be the effective figure after multiplication, not the paper value.
BTW, also bear in mind that the flat armour is applied AFTER physical resistance. So if an enemy has high phys res, (like Lokar, who has 82% phys res) the armour becomes that much more effective. But if you manage to reduce their phys res first, the armour subtraction will become much more marginal. Another reason why it is so very important for phys characters to have high OA to proc assassin’s mark.
I’ve done some napkin calculations and it seems to me that even WITH maul, those tiny sources of physical damage like 15 on the amulet would still fall under the armour threshold of many enemies.
Like many nemesis enemies have 1941 armour. Even if we reduce that by 35%, that 15 phys damage is going to be way under the armour threshold, so maul doesn’t really make a difference.
But it does help for any sources that are above the armour threshold, and it helps a lot for sources that happen to be JUST below the threshold.
Is that correct?