Recipe: Low Quality Rare Item of Same Type

Diadem is an excellent candidate for this recipe because it can always spawn +2 to All Skills regardless of ilvl. A Druid pelt with qlvl>75 (

Earth Spirit/

Sky Spirit/

Dream Spirit) can also be rerolled repeatedly without deteriorating its chance at +2 to Druid Skills.

The resulting item of this recipe, after multiple rerolls, will always have an item level approaching 2/3'rds of the characters level.
With some exceptions, it takes around 3 to 4 rerolls.
This follows the formula ilvl = [ilvl*0,4]+[clvl*0,4].
Thus, it isn't technically a recipe that lowers the ilvl of the item, it can actually raise it. A lvl 99 character rerolling an ilvl 9 rare item will eventually raise it to ilvl ~66.


As an aside, the reason

Diadem doesn't degrade its affix levels in this recipe is because, like all other items, it uses the quality lvl (and magic lvl) of the item to calculate the effective ilvl used to decide the lowest maximum possible affix level (yes, you read that right) for an item. This value doesn't change and is technically 103 for diadems; unlike its actual ilvl variable which will still approach two thirds of the characters level.
But this just doesn't matter in practice.

However.
This means that other items with an effective ilvl above 2/3'rds of the clvl, also cannot degrade beyond this point. For example,

Runic Talons can always roll affix levels up to at least level 63, even if the ilvl is much lower than that. Thus, rare

Runic Talons always have a chance to roll with +3 tab skills or +2 assassin skills, even if a character is level 1 when using this recipe. This is unlike the very close in qlvl

Feral Claws, which has a maximum possible alvl of 57 if the ilvl is 1, and thus cannot roll +3 tab skills (alvl 60) when degraded enough or found at a lower ilvl. This cannot be mitigated by the previously mentioned rule of 2/3'rds, because

Feral Claws (qlvl 58) need to have an item level of 80 to reach an affix level of 61, so a character would need to be level 120 to infinitely reroll rare

Feral Claws for +3 tab skills.

Each item type is unique in Diablo 2 due to its qlvl, and each item is unique due to its ilvl.

The highest affixes on rare jewels are Burning (+fre dmg) and Thunder (+lightning dmg) with ilvl 57. So any char with level 86 or higher can re-roll rare jewels and get all possible affixes with this recipe.

Explaining a little more

The ilvl will stabilize at 2/3 clvl, after a few cubing, because:

int(.4 * clvl) + int(.4 * (2/3 clvl)) = .... 2/3 clvl

before that, the ilvl will decrease on each cubing, if previous ilvl > 2/3 clvl;
or increase on each cubing, if previous ilvl < 2/3 clvl.

On the situation that resulting ilvl = 2/3 clvl

The alvl will be:

- base item has mlvl = 0 and qlvl = 1 (like rings, amulets and jewels)

alvl = 2/3 clvl

That's why clvl 86+ will guarantee alvl 57 for jewel (and will roll any jewel rare affix)
On the other hand even with a max alvl 66 at clvl 99, you will not be able to roll a lot of affixes desirable on end game rings/amulets

- base item has mlvl > 0 (like circlets)

alvl = MAX( 2/3 clvl, qlvl) + mlvl

That's why

Diadem (qlvl 85 and mlvl 18) will guarantee alvl 103

- base item has mlvl=0 and qlvl > 1 (most items)

alvl = MAX( 2/3 clvl, qlvl) - qlvl/2

if: MAX( 2/3 clvl, qlvl) < (99 – int(qlvl/2))
or

alvl = MAX( 2/3 clvl, qlvl) * 2 - 99

(it is the most common case for high clvl or qlvl)
That's why

Earth Spirit (qlvl 76) will guarantee alvl 53

Feral Claws (qlvl 78) will guarantee alvl 57

Sky Spirit (qlvl 83) will guarantee alvl 67

Runic Talons (qlvl 85) and

Dream Spirit (qlvl 85) will guarantee alvl 71
And any item with qlvl 75+ will guarantee alvl 50+ (enough for the 2 to class skill on any non-amulet/non-circlet that can roll with that affix)

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- affixes jewels:
https://classic.battle.net/diablo2exp/i ... wels.shtml
- general prefixes
https://classic.battle.net/diablo2exp/i ... /pre.shtml
- general suffixes
https://classic.battle.net/diablo2exp/i ... /suf.shtml