Hespera of SWC

Mana Regen

As you can see, there is a new variable being introduced by Blizzard, a base mana regeneration factor determined by your current level. For levels 58-70, these factors are:

0.011245
0.01111
0.010999
0.0107
0.010522
0.01029
0.010119
0.009968
0.009808
0.009651
0.009553
0.009445
0.009327

This factor scales inversely with level. Due to its relation within the new formula, as you level up, you will require more Intellect and more Spirit to derive the same level of return. This is of course consistent with previous Blizzard design philosophy which encourages continued gear progression.

1. After seeing the change in the patch notes, To get the formula for RatingBuster to work in 2.4, so the program was downloaded/installed the test patch. This program was used WinMPQ to peek inside and see if anything can found that is useful.

2. The mana regen file that used to contain the coefficients of the spirit regen formula for different classes, was changed so that its now the same for all classes. But something else has changed too, the coefficients used to be the same for all levels, it is now different for each level.

3. No where in the files could be found anything about INT, that means there's work to be done on the test server.

4. Raw data from the test server:
INT SPI REGEN_PER_SEC
21 22 3.526054932
19 20 3.049178196
23 24 4.025470329
20 21 3.28473313
22 23 3.773009134
22 22 3.609008623
27 22 3.998036219
19 25 3.811222864
19 20 3.049178196
26 22 3.923318935
24 20 3.42685659
18 25 3.709598137

5. Observe the data. From data with the same INT, that REGEN_PER_SEC is linear with SPI.

6. The first thing you do after you see that some thing is linear is to figure out if there are any constants. By using those with the same INT but with different SPI, for example:

19 25 3.811222864
19 20 3.049178196

Calculate the constant = 3.811222864 - (3.811222864 - 3.049178196) / 5 * 25 = 0.001

7. Pre-process the data to remove SPI and the constant from the function for curve fitting.
(1) X = REGEN_PER_SEC - 0.004
(2) regen/spi = X/SPI

INT regen/spi
18 0.148343925
19 0.152408934
20 0.156368244
21 0.16022977
22 0.164000397
23 0.167686264
24 0.17129283
26 0.178287224
27 0.181683464

8. Curve fitting, know what your looking for helps. According to past experience, blizzard formulas are relatively simple, the result should not be too complecated, it should be "smooth" in curve fitting terms.
The curve fitting routine tries to fit the data with some 10,000+ functions, and browsing through the results I see something really familiar.
A function a*x^0.5 with coefficient of a=0.0349649899816082
The coefficients for level 1 mana regen just happens to be 0.0349650010466576
So this is it.

9. The result: ManaRegen(SPI, INT, LEVEL) = (0.001+SPI*BASE_REGEN[LEVEL]*(INT^0.5))*5

10. Checking the formula with the data and it fits perfectly, 100% accurate.

Formulas

Important formulas for level 80 tanks:

4.9 Defense Rating = 1 Defense Skill
39.4 Dodge Rating = 1% Dodge
49.2 Parry Rating = 1% Parry
16.4 Block Rating = 1% Block
8.2 Expertise Rating = 1 Expertise
32.8 Hit Rating = 1% to Hit
46.0 Crit Rating = 1% to Crit
82.0 Resilience Rating = 1% less chance of being crit
32.8 Haste Rating = 1% Haste
1 Agility = 1 Ranged Attack Power
1 Agility = 2 Armor
1 Strength = 2 Melee Attack Power
2 Strength = 1 Block Value

Combat Skills

Unlike fixed percentages such as 2% critical strike chance, combat ratings diminish in potency as your character increases in level. 2% crit is the same at every level, while 28 critical strike rating grants 4% crit at level 34, 2% crit at level 60, and 1.27% crit at level 70. This allows Blizzard the ability to create and add new and better items to the world without eventually reaching a point where every character has a 100% chance to critically strike.

Below is the conversion for combat skills:

Type	Level 60	Level 70	Level 80	Stats
Expertise	2.5	3.9	8.2	1 expertise
Hit	10	15.8	32.8	1% hit chance
Critical Strike	14	22.1	45.9	1% critical strike chance
Spell Hit	8	12.6	26.23	1% spell hit chance
Haste	10	15.77	32.8	1% haste
Armor Pen	4.7	7.4	15.4	1% armor ignored

Defensive Skills

The impact on the defense skill and weapon skill systems is slightly more complicated. Many people do not realize these skills actually grant percentage-based benefits already. For example, every 25 points of defense skill grants a 1% dodge chance, 1% parry chance, 1% block chance, 1% increased chance to be missed and 1% decreased chance to be critically hit by physical attacks. Weapon skills have a similar effect for the attacker. Items will now grant skill rating rather than skill directly, and that will convert to an actual skill increase. Its important to note that parry and block rating does NOT work for druids since druids can't parry or block.

Below is the conversion for various ratings and stats:

Type of rating	Level 60	Level 70	Level 80	Equivalent Stat
Defense	1.5	2.37	4.92	1 defense skill before diminishing returns
Dodge	12	18.92	39.35	1% dodge chance before diminishing returns
Parry	20	23.65	49.18	1% parry chance before diminishing returns
Block	5	7.88	16.39	1% block chance before diminishing returns

Resilience

Resilience is a special new rating which Blizzard have created to reduce the effects of critical hits against your character. It has four components:

Type	Level 60	Level 70	Level 80	Stat
Resilience	25	39.4	82	- 1% less chance to be crit - 1% less mana drained - 1% less damage taken from dots - 2.2% less damage taken from critical strikes.

Expertise:
Expertise reduces the chance for your opponent to dodge or parry your attacks by 0.25% per point of expertise.
Its the best threat generation stat for Bear Form there currently exists.
Its NOT a requirement for raid DPS.

Armor

Basic Info
Armor reduces physical damage done against you by a certain proportion. The more armor you have the less damage you will take. By hovering your mouse over Armor on your Character screen, you can see the percentage value of this reduction for damage done by enemies that are at your current level. This percent reduction will actually fall as soon as you gain a level if you're still wearing the same armor. You haven't lost anything, it's merely showing you that your armor isn't as effective against monsters one level higher than you used to be.

Note that druid's bear form do not include magic armor in their boost to the armor rating. This is especially important for druids since bonuses received from armor kits, sets and green effects in general are not affected by bear form and Thick Hide.

Damage Reduction

Armor is there to reduce the amount of damage you recieve through melee attacks. However, the amount of Damage Reduction (abbreviated by %DR) you can achieve is capped at 75%. If you are fighting a level 70 mob or player, to achieve 75% DR you will need 31679 armor. Even when you got more armor then that, you will still take 25% of the damage they deal.

To calculate the amount of damage reduction you gain from X armor you can use the following formula for level 60 and above:

Damage Reduction = Armor / (Armor + 467.5 * Enemy Level - 22167.5 )

Following tables shows the various enemey levels and the armor needed to obtain a certain percentage of Damage Reduction.

	50% DR .	60% DR .	70% DR .	75% DR .
60 .	5883	8824	13726	17648
63 .	7285	10928	16998	21855
70 .	10558	15836	24634	31673
73 .	11960	17940	27907	35880
80 .	15233	22849	35543	45698
83 .	16635	24953	38815	49905

Damage reduction below level 60
In the level range of 1-59, the armor formula is changed and the old armor formula used prior to TBC is what you should consider if you haven't reached 60 or above yet.

Damage Reduction = Armor / (Armor + 85 * Enemy Level + 400)

"Diminishing Returns"

The more armor you have, the less Damage Reduction you will gain from each point of armor you add. Some people say that Armor thus has a Diminishing Return. Let's investigate this idea by taking a look at the Damage Reduction formula:

%Reduction = (Armor / (Armor - 22167.5 + 467.5 * Enemy_Level)) * 100

Now assuming that you're level 70 with 12423 armor in bearform, here's a chart showing how much of a difference adding 2750 armor will make in terms of damage reduction.

Armor .	Damage Reduction .	DR% Gained .	Armor Gained .
12423	54,06	54,06	N/A
15173	58,97	4,91	2750
17923	62,93	3,96	2750
20673	66,19	3,26	2750
23423	68,93	2,74	2750
26173	71,26	2,33	2750
28923	73,26	2,00	2750
31673	75,00	1,74	2750

So with the same exact increase in armor, we can clearly see that the Damage Reduction gained is less and less and less for the more armor you have.

Looking at this you might say that Armor has a "Diminishing Return", but lets look at this example:

Say you have 1000 hitpoints and you're fighting a mob that hits for 100 every second. Knowing how much armor gives a certain damage reduction, we can then figure out how much DPS the mob will actually be doing by simply subtracting 100 - DR%, since it's a simple 100 DPS. Then we can find out how long you will live by dividing 1000 health by the incoming DPS. Here are the results:

Armor .	DR % for level 70	Incoming DPS .	Time to Live .	Seconds of Life Gained .
12423	54,06	45,94	22	N/A
15173	58,97	41,03	24	3
17923	62,93	37,07	27	3
20673	66,19	33,81	30	3
23423	68,93	31,07	32	3
26173	71,26	28,74	35	3
28923	73,26	26,74	37	3
31673	75,00	25,00	40	3

Even though the damage reduction % gained is less and less as we add 2750 armor, the time to live is increased by the same EXACT amount each time. And thus, while there certainly is diminishing returns on "Damage Reduction", there is absolutely no diminishing returns on armor itself.