yes
Yes, but it's the inbetween where the problem lies
right now, if you're way below stat cap, you don't do a lot of damage. IE: if you're 80 STR below stat cap, there is not a lot of difference between +20 STR and +40STR.
but once you get to +60 STR, you will begin to notice a difference between +60 and +70. more on this a little later
I agree
my best guess is that damage is a function of several things
Base Damage (bd): determined by your STR and DPS score of your weapon. up to a cap.
f(atk): your atk vs the def of the target. no apparent cap. can act as a multiplier (your atk is higher than targets defense) or dampener (your attack is lower than targets def). this appears to be linear.
dLVL: diffrence in level between you and your target. most likely a log function. as large gaps show drastic differences than smaller gaps. mainly determines the cap to your damage. can act as a positive multiplier (you are higher level than your target) or a dampener (you are lower level than your target).
f(str): Your primary attack modifier vs primary defensive modifier of target. up to a cap. most likely a log function, as the closer you are to the threshold the bigger the difference. I believe this only acts as a multiplier. this does not seem to influence the function by a large amount.
so over simplifying: damage = [(base+f(atk))*f(str)]/dLVL
this is all based on looking at the testing of others. I personally have not tested any of this. especially since it is difficult to get a lot of +att with no +str etc.
some testing is also limited, so i'm filling the gaps with theory crafting and knowledge of how these formulas generally work.
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this means a couple of things
STR is used in two places on the formula. once to check your potential base damage. and again as a multipler of base damage.
IE: +10 str increases your base damage. but the modifier is low if your STR score is drastically below against the primary defense modifier of the target.
so you won't notice +10 str. you won't notice +20 str. and you may not notice all the way up to +50 str really.
10*0.01 is about equal to 50*0.015 when you're rounding to whole numbers. even with a difference of 40 STR. a difference of .1 damage vs .75 damage
but once you hit the magic threshold where STR checked against VIT starts to matter, you will begin to notice a bigger difference in return.
60*.1 is no longer about equal to 70*.15. even though the difference in STR is smaller, because the multiplier increases so much the damage is more noticible. a difference of 6 damage vs 10.5 damage. not super, super noticeable, but the affect is greater.
IE: the soft caps we see mean we have hit the base damage cap of our weapon, and are above the threshold of the target. so the only additional damage is gained from the +att. which is why it is more beneficial to just add +att after a certain point.