Game Mechanics: AC may not be working correctly

[MrSparkle001]

Originally Posted by Nizzarr [You must be logged in to view images. Log in or Register.]

Fixing AC on red99 to be broken like PvE would suck. It doesn't seem like AC does anything in PvE, but admittedly I haven't tested it extensively. So you fix it so it works properly in PvE then fix it on red99. Why would you purposely make it broken, you know?

[Aeolwind]

IIRC AC didn't do much on live either. It was a byproduct of pumping HP/STA/Relevant stat. It wasn't until Velious that it actually started to matter. AOW & Lord Vyemm made it pretty important.

Most of the mobs in Velious had sick, disgusting AC's. The '1' spam on Vulak is rather humorous from the logs I have.

KEEP WORKING ON THIS however. It is important to get the DB/DI working correctly with AC/Defense in general. It'll make it easier for me to kill you then =D.

[Splorf22]

Originally Posted by Splorf22 [You must be logged in to view images. Log in or Register.]

http://www.project1999.org/forums/sh...33&postcount=1

OK, I am guessing that Kanras directly implemented the formulas Treats found. Lets assume this is so. In that case

So we can assume that since Warriors and Monks have almost the same defense skill, their mitigation should depend almost entirely on equipped AC. The really good part about this post is the part we can take as more or less gospel by Kahvok, an EQ designer. They ran some tests around Luclin before the monk AC nerf:

Since warriors and monks both have the same defense skill, if the information in Treats' post is correct, then we can compare them directly. Going from 195 to 228 was good for a huge 6.5% reduction in damage. Going from 228 to 289 was good for an additional 5.5% reduction in damage. If there is some sort of diminishing returns (logical) then going from 155 to 195 as I did in my test should be MORE than 6.5% (40 vs 33, and in a higher part of the curve). That's well out of the range of error of the test. Again, these are the kind of numbers that make sense. AC was supposed to be good; no one would have figured out how to stack AC if +40AC was a 2-3% decrease in damage.

If you run the numbers, you'll find that 1AC is good for about a 0.11% increase in damage. 5000HP * 0.1% = 5.5HP, which is exactly the kind of ratio people used to quote. It's probably a bit less for ubermobs with huge attack values, and a bit more for XP mobs with lower values. A bit more if your AC is lower and a bit less if its higher. You get the idea.

Actually this thread is too depressing, lets just let it die. On Live Iksar warriors didn't have to go 3 years without armor upgrades. RAGE

P.S. Treat's post suggests the iksar bonus should apply to avoidance, but the actual wayback machine suggests mitigation. http://web.archive.org/web/200408221...#_Toc536608108 It sounds like no one was really sure. Mitigation would certainly make way more sense.

Aeolwind, I think this is a pretty reasonable estimate of how AC should work. I mean I can only bug the devs so much before I feel like an asshole. That's why I don't continuously bump my Loraen Bugs post. But there is a lot of stuff in there that I think is pretty important: resist caps, mage pets casting more, mobs being immune to memblur, AC, not getting weapons back from charmed pets.

[Aeolwind]

Aight, I'll throw some fuel on the fire then. 2 caveats, I'm posting from work and really not paying attention here and 2nd I am not a source dev, this is 'me' talking, not developer talking.

Values that modify 'attack'

• Raw Attack modifiers like Avatar/Firefist
• Strength stat and buffs
• Weapon Skill of weapon type (Slash, blunt)
• Weapon Skill of Wielding type (DW/2h)
• ??????????

Anything else?

Values that modify 'Armor'

• Item AC
• Shield AC
• Agility stat and buffs
• Defense skill
• Raw AC Buffs like Shield of Words

What else?

Values that modify avoidance

• Dodge
• Parry
• Riposte
• Dexterity stat and buffs maybe?

Anything else?

[happyhappy]

Agility stat increases AC, not Dexterity.

[Aeolwind]

Originally Posted by happyhappy [You must be logged in to view images. Log in or Register.]

Agility stat increases AC, not Dexterity.

Thanks, other game on the brain.

[Splorf22]

Aeolwind I'm told there is a #AC command for gms. How about you play with it and give us the results? I only did 150 hits each, so its not impossible I was just extremely unlucky.

[Aeolwind]

Originally Posted by Splorf22 [You must be logged in to view images. Log in or Register.]

Aeolwind I'm told there is a #AC command for gms. How about you play with it and give us the results? I only did 150 hits each, so its not impossible I was just extremely unlucky.

Give me a list of gear to have equipped, class, level, mob you want me to get pummeled by and the # the skills should be at. I'll let Nil decide what to do with the info after I gather it.

I'm not sure there is an AC Command honestly, never went looking. But using it would/could taint the results.

[Splorf22]

Originally Posted by Kahvok

Aggregate data from live servers at the time was taken to determine median-AC stats for each class. Parses were run against NPCs 3-4 levels lower, facing front. The characters had cleric AC and shaman agility buffs and faced the NPC. The results of the parse were consistent with statistical analysis of the formulas in code:

Class War Pal Mnk
Level 51 51 51
Raw Item AC 184 181 107
Agility 157 144 169
Dodge 3.4% 3.1% 4.4%
Block 0 % 0% 10.2%
Riposte 4.4% 3.9% 4.1%
Parry 5.2% 4.6% 0%
Skill Evasion 12.9% 11.5% 18.7%
Hit Rate 61.2% 61.3% 58.2%
Avg Hit 72.6 72.9 74.6
% Hits for Max 10.2% 10.5% 11.5%
Avg Dmg / Round 59.7 61.1 54.5
DPS 28.2 28.8 25.7


Class War Pal Mnk
Level 60 60 60
Raw Item AC 296 281 163
Agility 177 152 187
Dodge 4.3% 3.9% 4.9%
Block 0 % 0% 11.4%
Riposte 4.8% 4.3% 4.5%
Parry 5.8% 5.2% 0%
Skill Evasion 14.9% 13.4% 20.8%
Hit Rate 59.4% 59.7% 59.3%
Avg Hit 107.3 109.9 113.6
% Hits for Max 10.4% 11.7% 13.6%
Avg Dmg / Round 87.4 91.7 86.1
DPS 50.8 53.3 50


The problem was that the average plate-equipped warriors and knights had barely any lead on monks in mitigation, due to the monk bonus, but the monk still had the lead in evasion. Contrary to popular belief, this is what prompted the nerf to monk mitigation, NOT high-end monks being rampage tanks.

The changes had little effect on average level 51 warriors and knights, but since the average level 51 monk was over the new nerfed AC cap, it increased their average damage taken per hit and increased the percent chance of max hits (in the above example) to 13%. Monks who had better than this median AC were hit harder by the nerf since it lowered their effective AC even more. Level 60 monks with exceptionally high item AC (Ssra+) weren't hit quite as hard because the uncapping of item AC gave them more returns on AC over the class cap. The median level 60 changes looked like this (evasion, of course, remained the same):

Class War Pal Mnk
Avg Hit 106 108.9 121.3
% Hits for Max 9.8% 11.2% 18.4%
Avg Dmg 86.4 90.9 91.9
DPS 50.2 52.8 53.4

It should look like this. 51 and 60 warriors/monks, items to that that amount of AC, etc.

Also my understanding is the #AC command does not set your AC to X (which would be plausible) but instead simulates multiple hits against a given AC. However one of the GMs assured me that AC was indeed working and based his opinion on this command, so <shrug>

[Alecta]

Disclaimer: I cant step through my debugger right now, it's late, and I am out of town for the week, so this information might be wrong.

The AC system isn't very clean, but from what I can tell:

• The shield AC isnt handled any differently from normal AC
• Soft caps arent in place (?)

These are both due to the fact that the "NPC hitting a target" code uses the AC variable (which is what is displayed client side) and doesnt use the RealAC variable (which is what takes into account soft caps, shield AC, etc).

Also, I'd ignore the #ac_test command since that simulates "Player attacking something" and not "NPC attacking something" - and those follow different code paths.

NPC::ProcessAttack -> Mob::MeleeMitigation -> defender->GetAC()
vs
Client::ProcessAttack -> Client::ThrowATKvAC_D20I -> defender->GetRealAC()

Off topic: I am curious if the Monk AC bonus is working properly all the time. It seems that due to the order the bonuses are calculated, it might not be.

Anyway, will post more when I have more time to dig into this.