Item level

Template:Tocright The following text is an attempt to find the formulas used by Blizzard when creating items. It was originally posted by Hyzenthlei, Tauren Shaman 60 on EU-Zul'jin, in the Blizzard forums. Since good posts tend to disappear from there sooner or later, I copied and edited it here.

So far these calculations only work reliably for most equipment except Weapons. Weapons are a different beast entirely, they sometimes modify innate dps in ways that defy logic (or at least I dont have enough samples yet to get a reliable figure), and scaling seems to be different for them too. It is possible to apply these scaling routines to weapons, but dont be upset if they fall short on the high end things (they should work fine for most of the greens and blues below ilvl 65 though).

Terms and definitions

• ilvl — the effective level of an item (hidden in game), this is intimately related to its stats bonuses, armor and dps. The minimum level to use an item is ilvl – 5 or 60 whichever is smaller.
• ItemValue — the total value of stats on a given item, this value scales predictably based on item type, quality and ilvl. It is normalized to be linear with increasing ilvl for a given item type.
• StatValue — the amount of a given stat on an item, if a ring has 12 int, then it has an int statvalue of 12.
• StatMod — the weighting given to a specific stat, this is how stats are compared in value. Those are listed in #StatMods section.
• SlotMod — Weighting for predicting the value of an item based on equipment slot.

The numbers for StatMod are given in arbitrary units. I simply used a value of 100 for +heal, and reverse-engineered the factors for the other modifiers from there. Most probably Blizzard uses a different base, but it should not matter, as all that is important is the ratio between the stats, not the absolute value.

Calculating ItemValue

Here is the result of testing many forms of equations to see what did the best job of representing the way WoW itemization was handled.

ItemValue = [(StatValueX*StatModX)^1.5+(StatValueY*StatModY)^1.5+...]^(2/3)*SlotMod/100

This calculated itemValue matches Blizzards item level quite well (if the item quality is taken into account, see below).

A few remarks to this item value equation:

1. It is simple, but not so simple that it is just all the stats added together.
2. Each stat is taken to the 1.5 power. This isnt too fast of a growth, but it does cause a single high stat to be weighted fairly heavily. For example, one item could have +29 to Str and another +18/19 to both, Str and Sta, their ItemValues would be close enough to correspond to the same ilvl.
3. After summing the series of stats to the 3/2 power, the total sum is taken to the 2/3 power, this keeps the ItemValue from spiraling up and scaling with a power. After this modification the ItemValue scales linearly with ilvl.

StatMods

Due to the nature of the formula, an item of the same level can have more of a stat with a low stat mod, than with a high one. So for example 1% Crit = 14 Agility and 5 mana regen/5 = 12 Spirit.

Stat	StatMod
Armor	22
Attack Power	115
Ranged Attack Power	92
Attack Power vs (demons, beasts, undead)	76
Spell Damage (All Spells)	192
Spell Damage (One school)	159
Spell Healing	100
Magic Resist (One school)	230
Primary Stat (STR, AGI, STA, INT, SPI)	230
Defense	345
Regen per 5 sec (Health or Mana)	550
Damage Shield	720
Blocking Value	150
% chance to Block	1300
% chance to hit	2200
% chance to hit with all spells	2500
% chance to Dodge	2500
% chance to crit with all spells	2600
% chance to crit	3200
% chance to Parry	3600
Weapon skill (daggers)	720
Weapon skill (other)	550

Notes:

• +Holy has value of 210 on some items (according to Hyzenthlei), while for example Green Lens will have the same +34-36 to any school including Holy
• +Weapon skill (daggers) - Possibly just due to having more examples, most other weapon skill mods have several clumped onto one item

These stat mods were obtained by evaluating several thousands of items. Some values (esp. str, int, resists, +spell damage) are pretty reliable since they occur on many items and in large values. Others, such as %crit, %tohit, %spellcrit are much rougher as they dont appear much and then only in small values (1 or 2%). Items that have nothing else except for 1 or 2 of these less common stats sometimes wont fit in at exactly the ilvl you would expect because getting 1 more of that stat would push it far too high.

Another thing to consider, some of these weightings seem to be different on different item types. This is certainly the case for weapons, but also some stats on rings and necks as well. For example, rings can get higher resist values than their ilvl would imply, so they have a slightly lower StatMod for resists. They have a higher StatMod for x/5 health regen though. There are a few scattered stats that are this way, but overall they make a relatively small impact.

Item Slot Modifiers

Some item types usually have better stats than others. Helms for for example will give better benefits than bracers of the same ilvl. Be aware that a high number in this table means that the item has worse stats (than an item for a slot with a lesser number and the same ilvl).

• Head 1
• Chest 1
• Legs 1
• Hands 1.35
• Waist 1.35
• Feet 1.35
• Shoulder 1.35
• Trinkets 1.47
• Neck 1.85
• Back 1.85
• Wrist 1.85
• Ring 1.85
• Shield 1.92
• Off-hand 1.92
• 2h Weapon 1
• 1h Weapon 2.38

The values for weapons are only preliminary and should be used carefully.

Item Quality

In order to put the calculated item value in relation with the item level, one last step is neccessary: Factor in the item quality.

• Green (CalculatedItemValue + 9.8) / 1.21 = ilvl
• Blue (CalculatedItemValue + 4.2) / 1.42 = ilvl
• Purple (CalculatedItemValue - 11.2) / 1.64 = ilvl

Procs and uses effects

The stat mods table contains the 34 most frequently appearing stats. There are other stats which are sometimes unique or difficult to describe. All procs fall in this category, as do all Use:<do something> abilities. While these dont fit with an immediately obvious value, this system can be used to see what the blizzard item designers think they are worth and translate them into a stat-equivalent format.

Armor Scaling

Armor values on items follow a simple linear scaling pattern within certain limits. For example, mail armor scales linearly between certain ilvls, at which points the slope of the linear increase changes. One of these points is ilvl 45, above this point it scales more rapidly. Remember that an ilvl 45 item can be worn at lvl 40, and shamans and hunters get mail at 40. So they wanted mail to scale up fast for those classes, but without raising the amour values of pre 40 warriors too high (dont worry warriors, plate armor scales up even faster). An example of armor scaling is shown below.

Plate Chest Armor = (ilvl-44) * 8.9 + 428

The values from this scaling are for green plate chests. The armor value of rare or epic pieces is also very easy to obtain using a simple multiplier. If you really want to go into detail, you will notice that there are plate chests with ilvls below 44. Due to their ilvl they should be equippable below lvl 40 (if any class could) and follow a different scaling equation (which is why jouster plate stuff has such pitiful armor values compared to many other starting plate item, their ilvls are all low).

For Items of the same armor type (cloth, leather, etc) and the same ilvl

• Rare Armor Value = Green Armor Value * 1.1
• Epic Armor Value = Green Armor Value * 1.2

The exception to this is shields, which use a slightly different scaling

• Rare Shield Armor Value = Green Shield Armor Value * 1.125
• Epic Shield Armor Value = Green Shield Armor Value * 1.25

Of course there are items with much higher armor than others around that lvl. Those items are using the extra armor as an actual stat. Only this extra armor, above and beyond the predicted armor is considered in item weighting. So while the base armor level of an item is free, going higher will cost you other stats.

To find an expected armorvalue for a given item you will first need to know the scaling of that item type.

Do a search on thottbot for green items of that type, with lvl ranges of 44-46. Find the base armor they have. Then do the same for items of that slot at ilvl 61-63.

Then use

ArmorScaling = (higharmor - lowamor)/(highilvl - lowilvl)

this is the armor increase per ilvl for a green of that armor type. Once you have that, do

ArmorValue = (Desiredilvl - highilvl)*ArmorScaling + higharmor

This will give the value of a green at that ilvl.

Then multiply it by 1.1 for a rare, or 1.2 for an epic.

Let's try this on a stormrage helm, 183 armor, ilvl 76. Green leather helms: ilvl 45, armor 99 ilvl 64, armor 132

ArmorScaling = (132 - 99)/(64-45) = 1.74 armor/ilvl

(76 - 64) * 1.74 + 132 = 152.8 152.8 * 1.2 = 183.4 -> 183 armor

You can use this to find the ArmorScaling factor and expected armor for any item.

Examples

Lets try to see if we can predict an items ItemValue and then check it.

For this example we will use

Circle of Applied Force Binds when picked up Unique Finger Miscellaneous +12 Strength +22 Agility +9 Stamina Requires Level 60

This item has an ilvl of 75.

If we do the prediction calc above we find that it should have an ItemValue of about 72.1. If we do the calculations with the stat numbers of the item we find that its actual ItemValue is 71.1. Now why is this a whole point below what it should be? Thats because if any of the 3 stats on the ring were increased by just 1 point it would go above 72.1 and wouldnt be a valid ilvl 75 ring anymore (also I wouldnt put it past rounding errors).

We can also try this on

Cloak of the Shrouded Mists Binds when picked up Back 57 Armor +22 Agility +12 Stamina +6 Fire Resistance +6 Nature Resistance Requires Level 60 Item Level 74

This case is a tigher fit, estimated value using this system comes to 71.8, while the actual ItemValue of the cloak is 71.7.

And just so you casters dont think Im forgetting you (Im a healer too after all).

Shroud of Pure Thought Binds when picked up Back 57 Armor +10 Stamina +11 Intellect Requires Level 60 Equip: Increases healing done by spells and effects by up to 33. Equip: Restores 6 mana every 5 sec. Item Level 75

The estimated ItemValue of this cape is 72.7, while the actual value falls into the window well at 72.5.

You might be wondering why I keep showing capes. Its because of my next example of mishaps in item creation.

Also, I am showing some high end items to demonstrate that this system works, but many of my values and the scaling groundwork were obtained examining low - med lvl green and blue scaling. So it typically works well across all ilvl ranges.

Item Creation Gone Wrong - Mislabelling

Lets use this to examine a blizzard blooper.

Everyone probably knows of the Drape of Benediction.

It is a cape that seems horribly underpowered for where you get it from, Azuregos. Lets see how it shapes up using these tools. When you work out the numbers, the actual ItemValue of the Drape is 48.3, but an ilvl 67 Epic cape should chime in at 65.3 so something seems amiss.

Maybe its ilvl was too high? Lets see at what ilvl an epic cape should have an ItemValue of 48.3. This works out to be ilvl 48, seems a little low and random, maybe we are missing something.

Lets see what the ItemValue of a rare (blue) ilvl 67 cape would be, maybe that will tell us something. This value is 48.9 (with a lower bound of 48.2). The ItemValue of the drape of benediction falls right into this window.

So now we have the mysterious ilvl 67 rare (not epic) cape, drape of benediction. All of you who said it shouldnt have been an epic are exactly right. It was designed as a rare and flagged as an epic (a mixup like the snowblind shoes that are epic but originally tagged as a rare, though they fixed those).

Items Valued with unnaturally high ItemValue

There are also items that have been tweaked or changed by blizz that have item values far above what they should (and if you look carefully for discrepancies you will be able to tell which they are). But Im not going to go into specifics as I was asked by people who use them not to get them nerfed ;)

Tier 2 Sets

Many people have voiced opinions that tier 2 sets are not any better and in some cases worse than tier 1. In some cases of practicality for the needs of the class they are assigned to that may be true, but they were not balanced as worse. People also said that they were intentionally created to be even with tier 1 sets because people already got some in molten core, and that their stats would be raised after bwl comes out.

However, taking a look at item values for items in tier 2, they are exactly where they should be as ilvl 76 items compared to the tier 1 sets sitting at ilvl 66. The item designers just made choices on where to spend those stats that many people dont agree with.

So dont expect an across the board boost of tier 2 armor. The most they would do is move some of the allowed stats around, but they will likely stay ilvl 76.