The weapon was forged by the Huldra Brothers Brok and Sindri, back when they were relatively unknown blacksmiths, eager to make a name for themselves. Presenting the hammer to Thor, it quickly became the deadliest and favourite weapon of the Aesir, ensuring their dominance and allowing the thunder God to massacre scores of Jötnar with devastating ease.
After seeing the destruction wrought on giants with the very weapon they created, the two brothers suffered a profound sense of guilt. As a way to try and make up for their mistake they then forged the Leviathan axe, a weapon capable of rivalling even Mjölnir and gave it to the last guardian of the giants left in Midgard; Laufey.
The hammer is quite powerful, capable of killing most beings with one hit, and channelling vast amount of electricity.
- Noted as the hammer's only flaw, the handle was made too short due to a fly biting Brok on one of his eyes during the forging of the hammer.
- Despite possibly being the greatest weapon in the Norse World, only rivaled by the Leviathan and Surtr's sword, Odin made it so that it could not break the tree that trapped Mimir.
- In Norse Mythology, Thor had Magic Gauntlets and a Belt that not only enchanted the strength of Mjölnir, but also allowed Thor to heft the hammer with greater ease as it was very heavy.
- Though Brok and Sindri express guilt for all the destruction brought about by Thor's use of their hammer, they still acknowledge it as their greatest work, albeit bitterly.
- The hammer appeared before in God of War: Ascension's Multiplayer as an add-on and possible nod to the future of the franchise. This, however, is the Canon version of the hammer.
- In Norse Mythology, Magni and Modi were said to have inherited the hammer together, as it was so heavy it required both of them to wield it effectively. This does not appear to be the case in God of War however, as they are in open competition for the hammer.