Legacy Runewords crafted through the Horadric Cube sidestep the normal 2-socket item limit entirely - Diablo IV Season 15 mechanics

Season 15 shadow-dropped classic Diablo II-style Runewords: transmuting a normal-quality base item with the required Runes in the Horadric Cube produces a Runeword item that can require three, four, or even five Runes' worth of combined effect - impossible to fit on a normal item, which is hard-capped at 2 socketed Runes.

Detail

Because the Cube recipe consumes the runes directly rather than socketing them individually, the resulting Runeword is not bound by the equipped item's actual socket count. Runes are drawn from two categories (Evocation and Ritual) that can be freely mixed within a single recipe, and recipe order does not matter.

Why it works

The Cube-transmute recipe is implemented as a distinct crafting path (consuming a normal-quality base item plus a fixed Rune list) rather than the normal item-socketing system, so it is not subject to the same per-item socket cap that governs equipping Runes directly.

Numbers

12 runes documented (Amn, Ber, Eth, Ist, Ith, Lo, Mal, Ort, Ral, Sol, Tal, Tir) forming a documented set of Runewords (count varies by source: 17-19 cited).

How to use it

Treat Legacy Runewords as a separate itemization track from normal Rune socketing - farm and bank the specific Runes a target Runeword needs rather than trying to socket them piecemeal onto gear, since the payoff (3-5 combined effects on one item) only exists through the Cube recipe.

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