Kanai's Cube powers are passive abilities extracted from various legendary and set items in Diablo III: Reaper of Souls.
The extracted abilities are stored within the cube, and are not lost if replaced. While characters may only have up to 3 of them active, they can store all acquired essences within the cube, swapping them at any time when in town without losing essences they override.
At any given time, a character may have:
- One effect from either a weapon or an off-hand item (Quivers, Mojos, Sources, or Shields).
- One effect from a piece of jewelry (Rings or Amulets).
- One effect from any other piece of armor (Boots, Pants, Helms, Shoulders, Bracers, Chest Armor, Gloves, and Belts).
In addition, the following rules hold:
- Extracting power destroys an item.
- May extract power from item of any level, not necessarily 70.
- Power collection is shared among all characters of the same type on account. Seasonal characters roll over their collection when merging at the Season's end.
- In addition, legendary powers are Unique Equipped; as a result, one cannot gain the same power both from the Cube and from an equipped item.
- The passive traits granted by the Cube are completely independent from the character's actual passive skills, and use specialized slots that only fit for these traits.
- Weapon being one-handed or two-handed makes no difference: it will still count as a single essence.
- One cannot equip a Legendary Affix that is specifically designed for another class, or is bound to a class-specific item of another class, or to an item that the character cannot use for any reason.
- Ancestor's Grace, Corrupted Ashbringer, Halcyon's Ascent and Hellfire Amulet passives cannot be extracted into the Cube. Neither can the effects of Legendary Gems.
- Legacy items cannot have their powers extracted. An item obtained prior to patch 2.3 can have its power extracted, but only if it has not been changed since it dropped.
- Affixes with variable rolls retain their maximum roll in the Cube, so extracting is only performed once per item.
- The Cube interface shows players what Legendary Powers they are missing.
- Cannot extract Set properties. However, unique affixes of Krelm's Buff Belt, Krelm's Buff Bracers, Danetta's Revenge and Danetta's Spite can be extracted properly, but taking their essence may not complete the respective sets.
- For all purposes, the effect applies as if the item was equipped: that is, Arcstone and Unity ring essences will function properly when applied.
- Characters may use the powers that their class is "not supposed" to wield, but technically can. For example, Demon Hunters may (and sometimes should) take powers of Shields, which are rarely equipped due to the class's reliance on ranged weapons and quivers.
- Cosmetic effects of powers that have no real gameplay use (such as Slorak's Madness) can still be extracted, stored and applied, if, for whatever reason, players want to do so.
- As of patch 2.4, each Legendary power also displays an icon (see to the right) that indicates its status:
Solid diamond (top): cannot be extracted
Empty diamond (middle): can be extracted
Filled diamond (bottom): already extracted
Required Materials: