What is the Hellforge?
The exact location is always randomized, so there is no shortcut to finding the forge. The easiest way to find it is to start at either the stairs from the City of the Damned or the River of Flame waypoint. From there, follow the perimeter of the river until you get a quest pop-up.
After locating the Hellforge, defeat Hephasto The Armorer to obtain the Hellforge Hammer. Then equip the hammer and interact with the forge to destroy Mephisto's Soulstone and complete the quest. As a reward for completing this quest a number of gems or skulls and 1 rune drops.
What is the highest rune that can drop from the Hellforge?
The highest rune that can drop can from the Hellforge in Normal is an Amn rune. The highest rune that can drop can from the Hellforge in Nightmare is an Um rune. The highest rune that can drop can from the Hellforge in Hell is a Gul rune. Because a Gul rune is the highest rune drop from the Hellforge quest, this is generally regarded as the point where after the high runes start.
|normal||el, eld, tir, nef, eth, ith, tal, ral, ort, thul and amn|
|nightmare||sol, shael, dol, hel, io, lum, ko, fal, lem, pul and um|
|hell||hel, io, lum, ko, fal, lem, pul, um, mal, ist and gul|
The chance for any rune to drop from the rune drop table is equally spread. Each rune has a 1 in 11 chance to drop or 9.1%. This means that a Gul rune is just as rare as Hel rune from the Hell Hellforge quest. The drop chance is not affected by character level or player difficulty.
Additionally, you will also get one 1 perfect, 2 flawless, and 1 normal random gem or skull for each player completing the quest. Keep in mind that when you complete the quest with multiple players, only one rune will drop for the whole party!
Repairing the hellforge hammer
A popular myth states that a fully repaired Hellforge Hammer has better odds at dropping higher runes. This has already been debunked by Blizzard and there is no way to affect the rune drop chances. Every rune in the drop table will always have the same odds for dropping as the other runes.