The Iron Hearts are one of the most remarkable achievements of the Dwarven race. They were crafted in the ancient Dwarven stronghold of Stone Home. Iron Hearts are artificial bodies that serve as vessels for the souls and augmented hearts of Dwarves. The few Dwarves with the knowledge to create Iron Hearts are closely guarded and protected from threats.

Iron Hearts are constructed from various materials, typically featuring a metal frame that serves as a skeleton and metal plates that form their bodies. These plates may also be made of wood, ceramic, or composite materials. The only organic component of an Iron Heart is the heavily augmented heart located at the center of its chassis. Although Iron Hearts retain the memories of their former lives as Dwarves, they feel entirely detached from their past. Due to the unfeeling nature of their bodies, they struggle to connect with their former identities and often forge new paths, leaving significant aspects of their history behind. Their personalities always change after their transformation into Iron Hearts, shifting to align with their new forms.

Despite being capable of experiencing emotions, they find them difficult to express. This has led to Iron Hearts finding it challenging to connect emotionally with their Dwarvish creators. In Gevadun, people generally harbor a disdain for Iron Hearts; nonetheless, these beings have been granted full citizenship in all realms due to the protest of every Dwarvish citadel. The unnatural appearance of Iron Hearts, characterized by their lifeless gaze and mysterious origins, is what has made them unpopular among the people of Gevadun. The only beings, aside from Dwarves, who generally share a positive relationship with Iron Hearts are the Thri Kreen of Phoenix. However, this disdain is a generalization, as there are numerous tales of Iron Hearts forming bonds with all types of individuals.

The Iron Hearts were proposed by the Dwarvish tinkerer Gellor Clockmaker during the original Ankheg crisis of the Current Era (Era of Heroes) in 1394. After the crisis was resolved, the elder council granted Gellor minimal resources to work on his project. He toiled for years with an understaffed team to complete the Iron Hearts, and due to these limited resources, the project took much longer than anticipated. In 1552, during the second Ankheg crisis, Stone Home was sacked and nearly destroyed. As a last-ditch effort to hold the line, Gellor released the initial Iron Hearts, which played a crucial role in the miraculous defense of Stone Home. Since then, they have continued to produce new Iron Hearts. Whenever an important elderly Dwarf wishes to live on to pass wisdom or a young Dwarf suffers a mortal wound, they are permitted to become an Iron Heart.