OA and DA

[apocalypse80]

It's a given that the difference between the attacker's OA and the target's DA affects chance to hit.
They also affect the chance and magnitude of critical hits.

But defensive ability does more than that.

For a start , here's the probability to hit equation ;

(offensiveAbilityDV - defensiveAbilityDV + 1000) / 10

There is a second part , which I mistakenly thought applied to chance to hit , but it only applies to criticals.
Anyway , if the probability to hit is over 99% there is a chance to critical.

If the probability to hit is 99% or less you not only get a chance to dodge , but also take less damage from the attacks that that actually hit.

My experiment was done using an attacker of known damage (1268 per hit) and OA (807).
I used a naked skill-less char changing his DA with custom-made rings.

And this is the table showing the actual damage taken.



As you can see , if my DA is up to his OA + 9 , he does full damage.
At that point his chance to hit is 99.1% .

When I hit a DA equal to his OA + 10 I immediately get a 5.52% dmg reduction.
At that point the chance to hit is 99%.

Every point of DA over that offers an extra 0.05% dmg reduction.
So 100 points of DA would give an extra 5% dmg reduction , besides giving the guy a 10% chance to miss.

For example , if your DA is 210 points higher than his OA , he'll get a 21% chance to miss and do 15.52% less damage even if he hits.

I repeated this test with a much higher damage number to make sure that it's percentage based reduction.
And I also tried a much higher OA to make sure that it was proportional to the DA-OA difference.

Furthermore , this is NOT the attacker throwing full damage attacks and the target reducing them.
The attacker just throws attacks for less damage.
So this effect comes before everything else (resistances , armor etc).

Also , if the attacker is using a piercing weapon , him doing reduced physical damage will result in equal reduction to his piercing damage.
This only happens because piercing damage is a part of physical , any flat non-physical damage is not affected by OA and DA.

If this is not obvious , this is what happens when you get attacked but also what happens when you attack.


To sum this up ;

If the attacker's OA is equal to DA-9 or higher ; full damage , 99% or higher chance to hit , chance to critical
If the attacker's OA is equal to DA-10 or lower ; listed_dmg*(1-5,52%-(DA-OA-10)*0,05%) damage , (DA-OA)/10 chance to miss , no chance to critical.


Let me tie this up with an example ;

Attacker ; 790 OA , 1000 dmg - 30% of which is piercing (spear) , so a total of 700 physical and 300 piercing dmg.

Target ; 799 DA

The attacker does full damage , 700 physical and 300 piercing , which then has to go through resistances -> armor -> dmg absorbtion , in that order.

Target ; 1200 DA

DA is 410 points higher than OA , which gives a 41% chance to miss.
The first 10 points give a 5.52% reduction , the rest give 0.05% per point , so a total of 25.52% reduction.

The attacker does 1000*(1-25.52%) = 745 dmg , 70% is physical = 522 , 30% is piercing = 223.
So 522 physical and 223 piercing damage will then get modified by the target's defense.

I should repeat that THIS ONLY APPLIES TO MELEE COMBAT AND ONLY TO PHYSICAL DAMAGE.
Piercing damage is affected ONLY as a part of physical , if the attacker has a weapon with a flat piercing damage bonus then that flat bonus will not be reduced.

Oh and another thanks to Whisk33 for confirming this one.

[maul]

Coincidentally, I had twink my Haruspex to exploit extreme DA and he is now totally melee proof.

AT DA = 1700: known hard hitters such as leg crows , sandwraiths, mantids would barely manage to hit you. At this level it had put to shame my defense charcters

1800 = almost all melee mobs completely misses.
1900 = immuned/melee proof. you only had to deal only w/ archers and mages at this point.

Wraithlord however still manage to hit and Toxeus still gives huge damage. Need to test at higher DA levels when have time. Scorpos King/Manticore's headbite compeltely misses.

EDIT: Troglodytes-jailors can still hit at 1900 DA. They are probably had the highest
OA mob in the game.

[apocalypse80]

I've tried at 2000 and I got a char that really was impossible to hit , even for toxeus.
Of course his spells still hit.

My guess is that a DA a bit over 2k should be plenty.

For reference , VERY few things have over 1k OA or DA in legendary.
And most of them are heroes.
Of course monsters with specific skills (like battle rage) can get much higher.

Which pretty much makes 1k in OA and DA recommended values if you don't want to suffer offensively or defensively.

[maul]

Originally Posted by apocalypse80

My guess is that a DA a bit over 2k should be plenty.

I would say it would be an overkill unless you plan to farm Toxeus, 1700 DA is enough to completely ignore melee mobs, those that manages to hit have very minimal damage.

[Infares]

Kickass research apocalypse80.

I guess I should add some Dex afterall.

[maul]

Apocalypse!! have you tried a super critter character exploiting extreme OA?.

A Harbinger can exploit extreme OA and possibly dealing 150% damage for every hit at 2K OA level. This is before damage mod by onslaught. Someone may correct me on this.

btw, IMO adding dex to increase OA/DA is not worth it as dex gives basically same amount of OA/DA bonus. All OA/DA should come from gears.

[apocalypse80]

Yep , critting all the time for 1.5x dmg is very impressive.

Personally , particularly after this discovery , I feel a bit sorry that I didn't give my conq an extra +100 dex instead of strength.
It wouldn't make a huge difference , but it would make a difference.

It really is the same line of thinking , +100 dex wouldn't make a huge difference , but -100 str (out of 900) would be nothing.

I know there are items with +400 (or more) to defensive ability and there's a monster infrequent with a +140% defensive ability.
Is there anything similar only with offensive ability?

[maul]

I think gear bonuses on OA is a much less than that DA making it harder to reach 2K levels without sacrficing too much damage or resistances. I haven't seen too many OA bonuses on gears either.

[Felexitus]

also a hunter build gets +32% DA via wood lore youd have to go for warfare builds for OA and they ususally dont care about piercing, reducing dex value again

[Dejnov]

Two questions:

1) Do you know the formula for miss rates from missile fire due to dexterity?


2) Does the high DA values affect how much damage you take from a physical projectile if it hits you?


Dejnov.