Tempering interface
Tempering is a crafting system in Diablo IV, introduced in Season 4.
To carry out Tempering, the player must find Tempering Manuals, which blacksmiths can use to shape the qualities of items. Tempering allows players to add potent affixes to items. Most items can only have a single affix, while Ancestral Items can have two Tempered affixes from different categories.
Tempering durability indicates how many times an item can be tempered.
As of Season 11, players will be able to choose their affix rather than having it randomly applied. However, Tempering can only be conducted once per item. There is a chance for the Temper affix to become a Greater Affix. The affix can be restored indefinitely.