Bugmuncher
07-31-2013, 07:43 PM
general info found
Taking hits
when determining whether or not you are hit by an NPC, EQ goes through the calculation in this order:
Block, Riposte, Parry, Dodge, Shield Block, Miss
every mob has 20 possible values it can hit you for - every single mob in the game has a 20 point damage spread, without exception.
this spread is determined by this formula: DB+(DI*(1-20))
DB = damage bonus. a static number assigned to every mob. this number is reduced by Shielding.
DI = damage interval. a static number assigned to every mob. this is multiplied by (1-20) based on the mob's atk vs. your AC.
so, if we pretend that a mob has a DB of 10 and a DI of 10, you get the following:
10+10*(1-20)
min hit: 10+10*1 = 20
max hit: 10+10+20 = 210
if you assume 35% shielding you get:
min hit: 7.5+10*1 = 17.5
max hit: 7.5+10*20 = 207.5
warriors always get a 5% reduction to DI from whatever the final number (which basically translates to -1 DI, but not to drop under DI*1), and Defensive Disc and its variants give a 45% reduction to DI from whatever the final number is - meaning that a warrior in defensive is reducing the DI by half.
now, in EQ when you take all these factors, your AC vs. the mob's atk creates what's called your DI distribution - this is basically what percent of hits are where in the possible range of DI.
more AC = more hits will be lower in the DI spread.
that right there is what AC does for you. it makes more and more of the hits be on the low end of the spectrum.
now, since every mob has a different ATK value, and your DI distribution is always about mob ATK vs. your AC, that graph will look different for every mob that you ever tank.
but, it's a good idea for every tank to periodically pull up gamparse and load the Tanking tab for a given mob that you tank, and look at your DI distribution.
if you're interested in figuring it out... if you take the smallest difference between two regular hits (or use gamparse to graph it out like above) - that difference is the mob's DI.
(note that in most parses this is going be a little messy due to things like runes and vie and such changing your damage spread, in order to get it nailed down for certain you need to get 20 different hits without any sort of absorption - but even then, you can more or less figure it out)
for example, in the above chart, we learn that Daosheen has a DI of 199 (it's 199 point of damage difference between each hit)
if you take the lowest hit and subtract the DI, 1338 - 199 = 1139, which is Daosheen's DB.
so to figure out how much damage daosheen can do, using the damage formula, is:
1139+199*(1-20)
min hit: 1139+199*1 = 1338
1139+199*18 = 4721 (18 is the highest number on the char listed, and the there is an 8 point difference in the calculation here probably due to vie screwing up the damage numbers, but the math is still right)
max hit: 1139+199*20 = 5119
AC works by reducing the value of random (1-20) roll of the NPC damage formula.
(note that whenever AC is discussed, it must be remembered that in EQ, we the players do not know the exact formula for how AC works - we know what it does, and roughly how it does it, but there is no known formula which easily breaks NPC damage down to "X AC against Y atk reduces DI by Z", so much of the discussion about AC is conceptual terms, even though some values are known explicitly.)
the exact effect AC has on the value is highly variable and evidence suggests that in all instances it is a scaling value that is largely impacted by Diminishing Returns (ie, it hits a point where adding more AC has less and less of an effect).
the diminishing returns of AC are seen in-game in two different but important ways:
1. the AC softcap
2. DI reduction scaling
1. AC Softcap:
simply put this a value at which point adding more AC (via gear or buffs) no longer provides the full benefit listed on the item/buff.
2. DI reduction scaling:
this is kind of hard to describe simply in text...
basically the way combat and damage in EQ works is that the (1-20) DI portion of the formula is scaled in such a way that it's very nearly impossible to ever reach a point where you overcome every roll and get a DI1 on every hit.
even if you were to let a level 1 fire beetle hit you, it will still get some variance in its damage output, meaning it is getting something higher than 1 in its DI rolls.
the easiest way to express this is: there comes a point where your AC is high enough against certain mobs that adding more AC effectively does nothing against that mob.
(this behavior leads to one of two conclusions in terms of thinking about how EQ's damage formula most work:
1. AC effects the DI roll by a %, and as you get lower in the DI range % shifts become so small they effectively stop doing anything.
2. there is an absolute amount that AC can reduce the DI to, and once every hit is being reduced to that point the damage is just a random roll on the remaining available numbers.
(for example, if 3 is the lowest DI your AC can ever reduce a hit to, then damage is a random 1-3 DI, because you can never reduce that)
Taking hits
when determining whether or not you are hit by an NPC, EQ goes through the calculation in this order:
Block, Riposte, Parry, Dodge, Shield Block, Miss
every mob has 20 possible values it can hit you for - every single mob in the game has a 20 point damage spread, without exception.
this spread is determined by this formula: DB+(DI*(1-20))
DB = damage bonus. a static number assigned to every mob. this number is reduced by Shielding.
DI = damage interval. a static number assigned to every mob. this is multiplied by (1-20) based on the mob's atk vs. your AC.
so, if we pretend that a mob has a DB of 10 and a DI of 10, you get the following:
10+10*(1-20)
min hit: 10+10*1 = 20
max hit: 10+10+20 = 210
if you assume 35% shielding you get:
min hit: 7.5+10*1 = 17.5
max hit: 7.5+10*20 = 207.5
warriors always get a 5% reduction to DI from whatever the final number (which basically translates to -1 DI, but not to drop under DI*1), and Defensive Disc and its variants give a 45% reduction to DI from whatever the final number is - meaning that a warrior in defensive is reducing the DI by half.
now, in EQ when you take all these factors, your AC vs. the mob's atk creates what's called your DI distribution - this is basically what percent of hits are where in the possible range of DI.
more AC = more hits will be lower in the DI spread.
that right there is what AC does for you. it makes more and more of the hits be on the low end of the spectrum.
now, since every mob has a different ATK value, and your DI distribution is always about mob ATK vs. your AC, that graph will look different for every mob that you ever tank.
but, it's a good idea for every tank to periodically pull up gamparse and load the Tanking tab for a given mob that you tank, and look at your DI distribution.
if you're interested in figuring it out... if you take the smallest difference between two regular hits (or use gamparse to graph it out like above) - that difference is the mob's DI.
(note that in most parses this is going be a little messy due to things like runes and vie and such changing your damage spread, in order to get it nailed down for certain you need to get 20 different hits without any sort of absorption - but even then, you can more or less figure it out)
for example, in the above chart, we learn that Daosheen has a DI of 199 (it's 199 point of damage difference between each hit)
if you take the lowest hit and subtract the DI, 1338 - 199 = 1139, which is Daosheen's DB.
so to figure out how much damage daosheen can do, using the damage formula, is:
1139+199*(1-20)
min hit: 1139+199*1 = 1338
1139+199*18 = 4721 (18 is the highest number on the char listed, and the there is an 8 point difference in the calculation here probably due to vie screwing up the damage numbers, but the math is still right)
max hit: 1139+199*20 = 5119
AC works by reducing the value of random (1-20) roll of the NPC damage formula.
(note that whenever AC is discussed, it must be remembered that in EQ, we the players do not know the exact formula for how AC works - we know what it does, and roughly how it does it, but there is no known formula which easily breaks NPC damage down to "X AC against Y atk reduces DI by Z", so much of the discussion about AC is conceptual terms, even though some values are known explicitly.)
the exact effect AC has on the value is highly variable and evidence suggests that in all instances it is a scaling value that is largely impacted by Diminishing Returns (ie, it hits a point where adding more AC has less and less of an effect).
the diminishing returns of AC are seen in-game in two different but important ways:
1. the AC softcap
2. DI reduction scaling
1. AC Softcap:
simply put this a value at which point adding more AC (via gear or buffs) no longer provides the full benefit listed on the item/buff.
2. DI reduction scaling:
this is kind of hard to describe simply in text...
basically the way combat and damage in EQ works is that the (1-20) DI portion of the formula is scaled in such a way that it's very nearly impossible to ever reach a point where you overcome every roll and get a DI1 on every hit.
even if you were to let a level 1 fire beetle hit you, it will still get some variance in its damage output, meaning it is getting something higher than 1 in its DI rolls.
the easiest way to express this is: there comes a point where your AC is high enough against certain mobs that adding more AC effectively does nothing against that mob.
(this behavior leads to one of two conclusions in terms of thinking about how EQ's damage formula most work:
1. AC effects the DI roll by a %, and as you get lower in the DI range % shifts become so small they effectively stop doing anything.
2. there is an absolute amount that AC can reduce the DI to, and once every hit is being reduced to that point the damage is just a random roll on the remaining available numbers.
(for example, if 3 is the lowest DI your AC can ever reduce a hit to, then damage is a random 1-3 DI, because you can never reduce that)