Tempering Guide

The Tempering system enables players to customize their characters by adding powerful, build-defining affixes to their equipment. Normal and Sacred items can have 1 Tempering Affix added to them and Ancestral equipment can be given two Tempering Affixes, but Unique items cannot be Tempered. By using Tempering Manuals that are found randomly throughout the world of Diablo 4, players can learn Tempering Recipes that can be used unlimited times.

After selecting a piece of equipment, selecting the Tempering Recipe, and supplying the materials to a Blacksmith, a random Tempering Affix from the selected Tempering Recipe is rolled on the equipment. Players can reroll Tempering Affixes up to 5 times if they are unhappy with the results.

The Tempering Manuals and Tempering Recipes are categorized similarly to Legendary Aspects in the Codex of Power (eg: Resource, Mobility, etc). Each of the six categories corresponds to a subset of item types:

While most items can only have a single Tempering Affix (and Unique equipment cannot be Tempered), Ancestral items can have two Tempering Affixes. However, each Tempering Affix added to Ancestral equipment must belong to a different category. For example, an Ancestral Rare or Legendary Helm can have two Tempering Affixes, but one must be a Defensive Tempering Affix and the other must be Utility Tempering Affix. Rearranging the above list, we can see the full list of compatible Tempering Recipe categories for each equipment type:

The cost is based on the Item Power of the selected equipment. The more powerful the item, the more materials it requires. For example, tempering a 925 Item Power piece of equipment has the following cost:

When performing Tempering, a single Tempering Affix is picked randomly from the selected Tempering Recipe. If a player wants one specific Tempering Affix from a known recipe, there is a high probability that it won't be picked randomly on the first try. Players can reroll Tempering Affixes multiple times, up to the item’s Temper Reroll limit, a maximum of 5 times.

Tempering doesn't leave you an option to keep the previous result so you should never try to get a better roll on good affix unless you're comfortable with bricking the item

There’s a significant chance that players won't be able to get the exact tempering affixes that players want with the limit of 5 rerolls. For example, if a player wants one affix from a recipe with 3 affixes, and another affix from a recipe with 2 affixes, there is a 33% chance they get lucky with the first recipe, a 50% chance they get lucky with the second recipe, and a 16.67% chance they get lucky with both recipes on their first try. Most likely, one or both affixes won't be the affix they wanted. They have a total of 5 additional tries to reroll the affixes to get the ones they want. There is approximately an 84% chance to obtain both the affixes they want using 5 or fewer rerolls. This estimate is accurate for a player who wants one affix from a recipe with 3 affixes, and another affix from a recipe with 2 affixes.

Most optimal combinations of affixes come from recipes with 3, 4, or 5 affixes. Players would be wise to anticipate that they won't get exactly the affixes they want, especially if the recipes contain a large number of affixes. An otherwise perfect item can be "bricked" by the process of rerolling Tempering Affixes if the player has bad luck. For example, if a player wants one affix from a recipe with 4 affixes, and another affix from a recipe with 5 affixes, there is only a 49% chance of getting both acceptable affixes using 5 or fewer rerolls.

For that reason, it is advisable for players to pick at least 1 recipe that has a very low number of affixes, or multiple acceptable affixes. For example, if a player would be happy with either of two affixes from a recipe with 2 affixes, and 2 other affixes from a recipe with 3 possible affixes, there is a 99.9% chance of being satisfied with the results after using 5 or fewer rerolls.

Written by Slothmaster
Reviewed by Northwar, Dredscythe