Item level
Controls affix and tier eligibility on modifiable items. It usually comes from the area and monster level that produced the item.
Item generation and crafting

A higher item level unlocks stronger modifier tiers, but it does not guarantee those tiers and does not remove the lower eligible tiers from an ordinary crafting pool.
Drop calculation
The dropped item uses the resulting monster level. Item and monster levels are capped at 100.
| Source | Item level |
|---|---|
| Chest or non-monster source | Area level |
| Normal monster | Area level |
| Magic or rare monster | Area level +1 |
| Unique monster or boss | Area level +2 |
| Vendor item | Character level, subject to vendor cap |
Controls affix and tier eligibility on modifiable items. It usually comes from the area and monster level that produced the item.
Controls whether a character can equip the item. For equipment it is based on the base and the affixes currently present.
Sets the minimum area or monster level at which a base item becomes eligible to drop.
Irradiated grants +1 monster level. A relevant Coalesced Corruption or Cleansed map modifier can add another +1.
With the required Atlas specialization, high-tier rare equipment at item level 78 or higher can drop as an Exceptional base with over 20% quality or an additional augment socket.
Some item classes do not use item level, including currency, Runes and Soul Cores.