Item Generation: iLvl, Mods, and Affixes

First of all I’d like to give a big thanks to d3inferno for scraping the MPQ files to gather the data required for this post. They provide a ton of information on the inner workings of Diablo 3 that is not available anywhere else.

Item Level

Item Level, or iLvl, is a property that determines the affixes an item can roll. It represents the statistical “budget” of it’s power. As you progress through the game, you fight monsters that have a level that is roughly equivalent to your characters level. When you kill them, they drop items with an iLvl less than or equal to their monster level or (mLvl).

Here is a full list of items and their corresponding iLvl.

When you get to Inferno, all monsters have a chance to drop items up to iLvl 63, which is the highest in the game right now. Consult the table below to get an idea what the drop rates are for different acts:

ILVL 61 9 % 18% 19% 24%
ILVL 62 2% 8% 12% 16%
ILVL 63 0% 2% 4% 8%

Please note that these rates are subject to change. Blizzard often releases patches that will alter the way items drop from different areas, this table may already be out of date.

Mods vs Affixes

These terms are NOT interchangeable. Consider the following item:

This item has 2 affixes and 2 mods. The prefix “Chromatic” has the mod of “Resistance to All Elements” associated with it. The suffix “of the Fortress” has the mod of “+x Armor” associated with it.

This item 2 affixes and 3 mods. The prefix “Potent” has 2 mods: “+x Dexterity” AND “+x Vitality”. The suffix “of the Fortress” has the mod of “+x Armor” associated with it.

This item also has 2 affixes and 3 mods. The prefix “Potent” has 2 mods: “+x Dexterity” AND “+x Vitality”. The suffix “of Pain” has the mod of “+x Dexterity.” Since both affixes add to dexterity, the mods stack.

Most affixes have only 1 mod associated with them, but a few, like “of Pain” have 2.

Affix Level

To keep low level items from rolling powerful affixes that would make the game too easy, the “affix level” (aLvl) is capped at the iLvl. Below is a table that shows the various affixes and their corresponding aLvl’s for the “Attack Speed” mod.

Affix Name Mod aLvl
Keen Attack Speed Increased by 2% 1
Keen Attack Speed Increased by 2% 8
Keen Attack Speed Increased by 2% – 3% 14
Raiding Attack Speed Increased by 2% – 3% 22
Raiding Attack Speed Increased by 3% – 4% 30
Raiding Attack Speed Increased by 3% – 4% 40
Assailing Attack Speed Increased by 5% 52
Assailing Attack Speed Increased by 6% – 7% 61
Assailing Attack Speed Increased by 8% – 9% 62
Vanquishing Attack Speed Increased by 10% – 11% 63

Magic and Rare Items

Magic (blue) items can have either 1 or 2 affixes: 1 prefix and 1 suffix. Rare (yellow) items can have between 4 and 6 affixes. These can be all prefixes or all suffixes, or a combination of both, but there are rules in place to keep certain affixes from spawning together.

Affix Groups

Rares can only roll affixes that are from different “groups.” For example, you can’t get “Vanquishing” and “Raiding” on the same item. Similarly, you can’t get “of Conflagration and “of the Heavens” for an absurd amount of elemental damage. For a full list of affixes and their corresponding groups, please refer to this link.


* = may or may not be soon

Although it’s probably still a long way off, I’d like to make a couple predictions regarding what PvP will be like in Diablo 3 and some things to look out for:

  • Level Required Reduced. If Diablo 3 is anything like Diablo 2, there will be low level dueling. Having an iLvl 63 weapon at level 50 will be absolutely essential in order to compete. On weapons, the best roll on LRR is 18, on items with a max of iLvl 62 (such as jewelry and class-specific armor/offhands) the best you can do is 16.
  • Reduce Duration of Controlling Effects.  This is going to be a HUGE stat. It’s already fairly useful in PvE, but being able to recover from stuns, freezes, snares is going to make a huge difference when fighting actual people.
  • Build Diversity. Glass Cannons need not apply. I’m expecting a lot of 1-handed Crossbow + Shield builds from Demon Hunters.
  • Balance. Don’t expect it to happen any time soon. There will be imbalanced, broken, OP, unfair, (insert whiny word of choice) builds and you will lose to them. Thankfully, according to Bashiok, there will be an ELO rating system similar to the one used in Starcraft 2 so that on average, even the best players will win about 50% of the time. And I quote:
“More specifically, based off of your win/loss record. It’s not dissimilar from the matchmaker found in StarCraft II, which is based off of the Elo system used for Chess championships. Your win/loss and who they were against determines a ‘skill rating’, which is used to match up against other players of a similar rating. The intent is to get an even/fair match. Regardless of any individual factors like build, gear, or player ability, you’ll find some equilibrium where you’re facing off against players that you’re about as likely to beat as you are to lose. If getting better gear raises your abilities then you’re simply matched against players of a higher rating. Changing builds or just getting better at PvP could have the same effect. But regardless if you move up or down you’re ultimately still netting around a 50/50 win/loss as you’re always matching against similarly rated players.” -Bashiok
While we all wait with bated breath, here are a few images that were scraped from an MPQ file by Malu05 @ Diablofans:

Diablo 3 PvP Map

Diablo 3 PvP Map

Diablo 3 PvP Map

Diablo 3 PvP Map

Here is a reddit thread where many people speculate on PvP as well. Plenty of food for thought in there.

Patch 1.0.3

Patch 1.0.3, the most substantial update to Diablo 3 since it’s launch, went live yesterday morning. Tons of important stuff happened:

  • The attack speed nerf, which reduced existing values on items to nearly half of their original values, has rendered many builds nearly useless.

  • Increased cost on repairs will reduce, if not eliminate, graveyard-zerging elites and bosses.
  • Damage from monsters in Acts II, III, and IV in Inferno difficulty has been reduced. This. will make achieving enough damage reduction to not get 1-shotted a much more reasonable goal.
  • Drop rates have been changed as per this table:

New drop rates for 1.0.3

Item Hell Act III/IV Inferno Act I Inferno Act II Inferno Act III/IV
iLvl 61 9 % 18% 19% 24%
iLvl 62 2% 8% 12% 16%
iLvl 63 0% 2% 4% 8%

This is a very important change, because it’s actually a nerf. The best gear previously had a much better than 8% chance to drop in act 3 and 4, and many previously viable farming routes are no longer worth running.

In general, the meta-game seems to be shifting away from “glass-cannon” builds.

Read the full patch notes here