View Full Forums : AC and diminishing returns (long)


Ender
10-16-2005, 07:25 PM
There have been a lot of arguments about whether or not armor class suffers from diminishing returns. I've seen some pretty compelling arguments that say it does, however I believe armor is on a linear scale with no diminishing returns when you look at realistic game situations.

To prove my point I will look at six different cases you might run into in the game. In each case I will be using a lvl 60 tank with 5000 hps and a healer with a 2000 hp heal that costs 1000 mana and a 5000 mana pool. They will be fighting a lvl 60 mob that does a steady 500 melee DPS. These numbers are arbitrary but they are all constants and you could pick any numbers and get the same results. I will NOT be taking mana regen into effect, but will comment on it. I will look at four data sets for each case. The numbers in parenthesis shows the change between each data set. The conclusions are in italics for anyone that wants to skip the math.

0 AC = 0% reduction.
4000 AC = 42.11% (+42.11) reduction.
8000 AC = 59.26% (+27.15) reduction.
12000 AC = 68.57% (+9.31)reduction.

Looking at those numbers the gut instinct is to say its obviously diminishing but that is not actually the case.

Case 1 : Soloing an elite mob.

When trying to solo an elite mob the most important factors for a tank are DPS and health. The longer his health holds up the longer he can apply his DPS.

0 AC - 500 DPS taken, tank dies in 10 sec
4000 AC - 289.45 DPS (211.55 reduction) taken, tank dies in 17.27 sec (7.27 sec increase)
8000 AC - 203.7 DPS (85.75 reduction) taken, tank dies in 24.54 sec (7.27 sec increase)
12000 AC - 157.15 DPS (46.55 reduction) taken, tank dies in 31.82 sec (7.27 sec increase)

At first glance looking at the DPS reduction this would appear to show diminishing returns, however in realistic terms the tanks survival rate increases by a steady 7.27 seconds every 4000 AC. This means every 4000 AC he does 7.27 seconds more of DPS which directly increases the strength of mobs he can solo.

Case 2: Tank soloing normal mob.

Everyone goes solo from time to time whether it be for XP or just to farm cash, they usually target trivial mobs while they do it. When fighting these mobs whats important is how many you can kill back to back before resting. Assuming the tank takes 8 seconds for each kill.

0 AC - 500 DPS taken, 4000 health lost in 8 sec.
4000 AC - 289.45 DPS taken(211.55 DPS reduced) - 2315.6 health lost in 8 sec. (1684.4 health saved).
8000 AC - 203.7 DPS taken(85.75 DPS reduced) - 1629.6 health lost in 8 sec. (686 health saved).
12000 AC - 157.15 DPS taken(46.55 DPS reduced) - 1257.2 health lost in 8 sec. (372.4 health saved).

In this case AC seems to show diminishing returns since the DPS reduction is lower in every case and the health saved is reduced in each case, but this isn't really the case. When a tank is soloing whats really important is how often he needs to rest. He fights until his HPs are low and then he eats or bandages or heals himself to full and repeats. So lets look at how many mobs the tank can kill before resting, we'll assume he rests every time he reaches 1000 HPs.

0 AC - 4000 health lost per fight so needs to rest every 1 mob.
4000 AC - 2315.6 health lost per fight so needs to rest every 1.73 (+.73) mobs.
8000 AC - 1629.6 health lost per fight so needs to rest every 2.46 (+.73) mobs.
12000 AC - 1257.2 health lost per fight so needs to rest every 3.18 (+.73) mobs.

The realistic effect of AC on soloing as a tank is linear. Every 4000 AC in this example improves the number of mobs he can kill before resting by 0.73. If he is trying to maximize XP/hour from soloing then raising his AC always helps the same amount, there are no diminishing returns.

Case 3 : Grouped hard pulls.

In instances the group is capable of resting after every fight, the most important thing is the healer not running out of mana. If the healer can heal 5 times he in effect gives the tank 10,000 more hps for 15,000 effective hps.

0 AC - 500 DPS, healer runs out of mana and tank dies in 30 sec
4000 AC - 289.45 DPS, healer runs out of mana and tank dies in 51.82 sec (21.82 sec increase)
8000 AC - 203.7 DPS, healer runs out of mana and tank dies in 73.64 sec (21.82 sec increase)
12000 AC - 157.15 DPS, healer runs out of mana and tank dies in 95.45 sec (21.82 sec increase)

Every 4000 AC increases the duration of healing by 21.82 seconds. The length of time the healer's mana pool lasts directly relates to what a group is capable of killing in an instance and in this case AC does not diminish.

Case 4 - Grouped Hate Production.

One of the biggest keys to succeeding in a group is the tank efficiently holding aggro. The less often the healer needs to heal the easier it will be for the tank to do his job as less hate is produced through healing.

0 AC - heals every 4 sec
4000 AC - heals every 6.91 sec (2.91 sec increase)
8000 AC - heals every 9.82 sec (2.91 sec increase)
12000 AC - heals every 12.73 sec (2.91 sec increase)

The rate at which the tank is healed is linear when compared to AC. Every 4000 AC increases the length between heals by 2.91 seconds. This in effect increases efficiency since again the longer between heals the more mana regen helps out. It also increases the tanks DPS as he can hold aggro more with damage abilities and less with debuffs.

Case 5 - Group Efficiency

The speed at which a group kills mobs is related to how often the healer has to drink.

0 AC - 250 mana/sec, healer runs out in 20 sec
4000 AC - 144.72 mana/sec (105.28 decrease) - healer runs out in 34.55 (+14.55) sec
8000 AC - 101.83 mana/sec (43.89 decrease) - healer runs out in 49.10 sec (+14.55) sec
12000 AC - 78.55 mana/sec (23.28 decrease) -healer runs out in 63.65 sec (+14.45) sec

Again this looks like diminishing returns, the mana used per second decreases more and more over time. The length of time the healer can heal for does not diminish. To maximize efficiency the group kills until the healer needs to drink and then he drinks to full and repeat. We'll again assume the mobs are dying in 8 seconds.

0 AC - 2000 in 8 sec, med every 2.5 mobs
4000 AC - 1157.76 in 8 sec, med every 4.32 mob (1.82 increase)
8000 AC - 814.64 in 8 sec, med every 6.14 mob (1.82 increase)
12000 AC - 628.4 in 8 sec. med every 7.96 mob (1.82 increase)

Every 4000 AC increases the number of mobs the group can kill before meditating by 1.82. This shows a linear relationship for armor reduction.

Case 6 - Raids

The most important thing for a raid tank is to not die from one round of combat. As was shown previously in case 3 the duration of healing is linear and this case shows that the ability to absorb burst damage is linear as well.

0 AC - 5000 dmg will one round the tank
4000 AC - 8637.04 (+3635.07) dmg will one round the tank
8000 AC - 12272.95 (+3635.88) dmg will one round the tank
12000 AC - 15908.37 (+3635.42) dmg will one round the tank

Every 4000 AC increases the damage it takes to kill the tank in a single round by 3635 showing a linear increase.

It doesn't matter if the tank is solo, grouped, fighting hard mobs, killing easy things or acting as a raid tank, in every situation AC's effects are linear. While its easy to just look at the damage reduction or damage taken and say they diminish that is not the reality in game when looking at meaningful game situations. This also shows that Thick Hide actually gets stronger the higher your AC is since it is a percentage AC gain, it is a very strong talent for bear and moonkin forms.

Falloraan
10-17-2005, 12:00 PM
well said, thank you for posting this

gwmort
10-25-2005, 07:03 PM
I am impressed with the mathematical analysis, would like to see more treatments of other game stats and their relative benefits.

Accretion
10-26-2005, 01:39 PM
Nice post. Thanks for the info.