Some problems with the combat code:

[Furniture]

I have been analyzing the combat code as of late, and there are some things that look like need to be addressed to make it more live like.

1)EDIT - accuracy problem solved

2) Mitigation - I am also seeing issues with the Mitigation formula not properly reducing the damage to the proper interval. A level 40 with banded armor gets nearly identical damage mitigation to a level 40 with fine plate. I know this amount of AC difference is trivial at high end game, and changes must be made accordingly to end game content, but in its current state this is no where near live.

It is a messed up formula where if you are less then max level, playing in lower expansion zones, having a little bit of AC will give the same effect as having a high ac. For any server using this code and stock lower level zones/gear drops the 1-60 game is severaly 'bugged' so to speak.

[Kayen]

Your 'agility' statistic and your 'defensive skill' which makes up a portion of your AC value is what contributes to your 'chance to avoid melee' in the source.

Accuracy from items and spell effects is accounted for as well.

When YOU are attacked it checks the difference in level between YOU and attacker at derives the base line chance that you will be hit.

Then it subtracts from that value YOUR ( AC component[agility factor, defensive skills], spell and item bonus AVOIDANCE)

Then it adds back to that value the ATTACKER accuracy modifiers. (Accuracy from items / spells, Chance to Hit spell effects).

The final chance to hit value is then rolled to determine initial hit vs miss.

[Furniture]

Ok that makes sense, however it seems like the formula is changed a lot in the chance to hit code, where in the avoidance code it calculates it as:

int avoidance = (acmod() + ((GetSkill(DEFENSE) + itembonuses.HeroicAGI/10)*16)/9);

So does that mean the calculation of avoidance with this formula (which is the correct formula based on research) has nothing to do with combat and just for show in your AC values?

[Furniture]

When it comes to mitigation, what I'm looking to fix for low to mid game combat is basically:

1) Take more damage if mitigation rating is low

2) Take less damage if mitigation rating is high


Since these are tuned for higher level combat where you are expected to have very high mitigation it seems correct but like I said for lower level combat it is off.

I'm convinced theres somehow I can alter something in the following somehow to achieve my desired effects, but I havent figured it out yet:

float d = 10.0;
float mit_roll = MakeRandomFloat(0, mitigation_rating);
float atk_roll = MakeRandomFloat(0, attack_rating);

if(atk_roll > mit_roll)
{
float a_diff = (atk_roll - mit_roll); //200
float thac0 = attack_rating * RuleR(Combat, ACthac0Factor); // 440
float thac0cap = ((attacker->GetLevel() * 9) + 20);
if(thac0 > thac0cap)
{
thac0 = thac0cap;
}
d -= 10.0 * (a_diff / thac0);
}
else if(mit_roll > atk_roll)
{
float m_diff = (mit_roll - atk_roll);
float thac20 = mitigation_rating * RuleR(Combat, ACthac20Factor);
float thac20cap = ((defender->GetLevel() * 9) + 20);
if(thac20 > thac20cap)
{
thac20 = thac20cap;
}
d += 10 * (m_diff / thac20);
}

if(d < 0.0)
{
d = 0.0;
}

if(d > 20)
{
d = 20.0;
}

float interval = (damage - minhit) / 20.0;
damage = damage - ((int)d * interval);
}

Any suggestions?

[Furniture]

Here is some parsing info:

I parsed a few different levels, 1-50 and found identical results.

Heres an example, a lvl 26 max defense character vs a white con lvl 26 warrior mob, on all values i parsed for a while until the data was rarely changing after time, my consistent results leads me to believe I have parsed for a significant amount of time

Ungeared: AC - 323 Mitigation - 11
AVG Hit from mob - 37
Max Hit from mob - 52

Full set of banded: AC - 466 Mitigation - 154
AVG Hit from mob - 25
Max Hit from mob - 52

Full set of fine plate: AC - 537 Mitigation - 225
AVG Hit from mob - 24
Max Hit from mob - 52

As you can see, there was no significant damage mitigation increase from 154 mitigation to 225 mitigation, but there was a significant increase from 11 to 154.

What could be the cause?

[Goryani]

Originally Posted by Furniture

Here is some parsing info:

I parsed a few different levels, 1-50 and found identical results.

Heres an example, a lvl 26 max defense character vs a white con lvl 26 warrior mob, on all values i parsed for a while until the data was rarely changing after time, my consistent results leads me to believe I have parsed for a significant amount of time


Ungeared: AC - 323 Mitigation - 11
AVG Hit from mob - 37
Max Hit from mob - 52

Full set of banded: AC - 466 Mitigation - 154
AVG Hit from mob - 25
Max Hit from mob - 52

Full set of fine plate: AC - 537 Mitigation - 225
AVG Hit from mob - 24
Max Hit from mob - 52


As you can see, there was no significant damage mitigation increase from 154 mitigation to 225 mitigation, but there was a significant increase from 11 to 154.

What could be the cause?

Unfortunately, these results are not sufficient to determine if any problem exists.

Due to the way the D20 system works, infinite AC should result in an average damage per hit around the 4th DI interval. No min hit is listed but a mob that hits for 52 max and average of below 32 should have a min hit around 14. That would put DI = 2. The 4th DI would be ~18 damage. Therefore, infinite AC should result in an average hit of 18.

Mitigation is subject to diminishing returns (and not just because of any softcaps). A min hit can't be mitigated any lower. Extra AC has zero effect on min hits at the old AC value. It doesn't seem unreasonable that banded is already well into diminishing returns territory. The test needs to be repeated with leather and silk equivalent. It also needs to be repeated for upgrading more than the 7 slots covered by banded/fine plate.

Originally Posted by Furniture

I do admit I did exaggerate a bit, but the parse clearly shows in its current state trivial mitigation between banded and fine plate and to me that is definitely a huge flaw. Perhaps the issue all along was the STR of the mobs being too high, I will test and see how it goes, thanks.

A 4-5% increase in mitigation is not trivial. It's actually quite large. How many extra swings does it take to kill the fine plate geared toon compared to the banded toon? How much time is that?

[Furniture]

Originally Posted by Goryani

Due to the way the D20 system works, infinite AC should result in an average damage per hit around the 4th DI interval. No min hit is listed but a mob that hits for 52 max and average of below 32 should have a min hit around 14. That would put DI = 2. The 4th DI would be ~18 damage. Therefore, infinite AC should result in an average hit of 18.

Mitigation is subject to diminishing returns (and not just because of any softcaps). A min hit can't be mitigated any lower. Extra AC has zero effect on min hits at the old AC value. It doesn't seem unreasonable that banded is already well into diminishing returns territory. The test needs to be repeated with leather and silk equivalent. It also needs to be repeated for upgrading more than the 7 slots covered by banded/fine plate.



A 4-5% increase in mitigation is not trivial. It's actually quite large. How many extra swings does it take to kill the fine plate geared toon compared to the banded toon? How much time is that?

While this seems like it would be correct, when you actually add in absurd amounts of AC directly, mitigation is reduced to the first interval 100% of the time.


The way I've dealt with this whole thing which works quite well, is by adding a bonus to the amount of AC. At varying levels of increased AC, there is significant mitigation differences between armor sets.

[jsr]

While this makes sense, when increasing or decreasing a mobs strength by large amounts, I have seen absolutely 0 change in mitigation.

It seems to work pretty well for client attacks though

I'd expect this outcome if you changed an NPC's stats without doing a #repop.

[ChaosSlayerZ]

i would have simplified/rewritten entire combat formula from scratch and make it much
more straightforward and not level based at all, so ac/stats play more significant role....
Of course it won't be live-like anymore.... so forgive me for ranting

[KLS]

In all fairness so would I but alas. The reason why there's a huge jump from ungeared to geared then a small one beyond that is because there are very severe AC softcaps in play.

[Furniture]

The plate softcap for raw ac is 300, im not hitting anywhere close to that with my fine plate.

Unless Im missing something I dont see how the softcaps are effecting my mitigation, seeing how

if(armor > softcap)
{

should be coming out false



I think I will mess with the ACthac20Factor and ACthac0Factor rules and see if I can get desired effects that way.

[lerxst2112]

Originally Posted by Furniture

should be coming out false

No reason to ever say "should be". Add some code to tell you for certain if it is true or not.

[Furniture]

well i understand how this works enough to know that im not hitting that armor softcap so I wonder if theres another cap that im not seeing thats effecting this somehow

[Furniture]

unless the softcaps kls mentioned is the thac0cap and the thac20cap?

EDIT - I removed the thac0cap and the thac20cap and still no change in parse data

[Furniture]

EDIT - Nevermind, still need help here


I'll probably just have to add a + % bonus on armor rating while raising npc's attack rating so they hit for proper intervals, will be a lot of testing at varius levels to get things right but thats probably how ill have to do it