If you want to upgrade rare or unique items in Diablo 2: Resurrected, then you need to make a specific Horadric Cube recipe. The content of the recipe varies according to the items you need to upgrade, but it will definitely include a Perfect gem, and these gems will not drop under Normal difficulty. If you choose Hell difficulty, you will always get one. In Act I on Nightmare difficulty, they will start to drop randomly. Only when you explore a lot of places on Nightmare difficulty, you may be lucky enough to get a Perfect gem.

You don’t need to change the modifier when upgrading a rare or unique weapon, change the base weapon from Normal to Exceptional, or from Exceptional to Elite. So basic statistics like damage or defense will be improved. Once these basic statistics are affected by the percentage modifier, then its upgrade will cause great changes.

The rare item upgrade recipe is as follows:

Normal rare armor to Exceptional: Normal rare armor, Thul rune, Ral rune, Perfect Amethyst

Normal rare weapon to Exceptional: Normal rare weapon, D2R Items Amn rune, Ort rune, Perfect Sapphire

Exceptional rare armor to Elite: Exceptional rare armor, Pul rune, Ko rune, Perfect Amethyst

Exceptional rare weapon to Elite: Exceptional rare weapon, Um rune, Fal rune, Perfect Sapphire

The unique items upgrade formula is as follows:

Normal unique armor to Exceptional: Normal unique armor, Shael rune, Tal rune, Perfect Diamond

Normal unique weapon to Exceptional: Normal unique weapon, Sol rune, Ral rune, Perfect Emerald

Exceptional unique armor to Elite: Buy Diablo 2 Resurrected Runes Exceptional unique armor, Lem rune, Ko rune, Perfect Diamond

Exceptional unique weapon to Elite: Exceptional unique weapon, Lum rune, Pul rune, Perfect Emerald

Therefore, if you want to obtain these recipe materials in the game, you need to constantly explore in the more difficult modes such as Nightmare or Hell, during which you need to spend a lot of time to get a material you need. In MMOWTS, there are various Diablo 2 Resurrected Items for sale, so you no longer need to spend a lot of time exploring in the map, you only need to buy them there to use them immediately.