Infernal Iron is one of the most sought-after materials in Baldur’s Gate 3, not because of its raw market value, but because it functions as the literal lifeblood for one of the game's most beloved companions. This dented, black metal, etched with a faint red glow and echoing with the distant screams of the Nine Hells, is the only substance capable of stabilizing Karlach’s internal engine. Beyond its role in "The Hellion's Heart" quest, it serves as the primary component for crafting the Flawed Helldusk armor set, a formidable gear choice for the mid-game.

Finding these pieces requires a keen eye and a willingness to explore some of the most dangerous corners of the Sword Coast. Since some locations become inaccessible as the story progresses, understanding where and when to secure this metal is vital for anyone looking to maximize their party's potential or pursue a romance with Karlach.

The Role of Dammon the Smith

Before hunting for the metal, players must identify the individual capable of working it. Dammon is a tiefling blacksmith who possesses the rare knowledge of infernal mechanics. His survival is a prerequisite for using Infernal Iron. If Dammon dies during the various conflicts in the game—such as the raid on the Emerald Grove or the fall of Last Light Inn—the ability to process Infernal Iron effectively ends.

Dammon appears in three primary locations across the acts:

  1. Act 1: The Emerald Grove. He is found in the Hollow, working at a forge near the other tiefling refugees. This is where the first engine upgrade usually occurs.
  2. Act 2: Last Light Inn. If he survives the first act, Dammon sets up shop in the stables of the inn within the Shadow-Cursed Lands. He can perform the second engine upgrade here and begin crafting armor.
  3. Act 3: Lower City of Baldur’s Gate. Dammon operates the Forge of the Nine, located near the Devil’s Fee. In this final stage, he can process any remaining iron or specialized variants like Enriched Infernal Iron.

Infernal Iron Locations in Act 1

Act 1 offers several opportunities to find Infernal Iron, allowing for the first stabilization of Karlach’s heart early in the journey.

The Blighted Village Blacksmith’s Basement

This is typically the first piece most players encounter. In the Blighted Village, there is a house used by a former blacksmith located north of the waypoint. Upon entering, players will notice a large hole covered by calcified cobwebs in the middle of the room. Burning away the webs allows access to the basement.

Inside the basement, there is a wooden chest sitting on a high scaffold (X:-434, Y:-370). It is important to note that this chest is rigged with a pressure plate trap. Disarming the trap requires a successful Sleight of Hand check. Alternatively, players can use Mage Hand or a ranged attack to trigger the trap from a safe distance before approaching. The Infernal Iron is secured inside this chest.

The Shattered Sanctum (Goblin Camp)

Deep within the Goblin Camp lies the Shattered Sanctum, the throne room of the hobgoblin leader Dror Ragzlin. Directly behind Ragzlin’s throne is a heavy iron gate leading to his private treasure hoard (X:298, Y:66).

There are multiple ways to access this room. The most direct method is defeating Dror Ragzlin and looting his body for the key. For those preferring a stealthier approach, the lock can be picked, though it requires a high difficulty roll. Inside the room, among various piles of gold and artifacts, a piece of Infernal Iron sits within one of the crates. Because this area is heavily guarded, it is advisable to clear the surrounding goblins or utilize invisibility to reach the treasure.

The Zhentarim Hideout

The Zhentarim Hideout, accessible through a secret entrance in Waukeen’s Rest, contains a locked storage area at the back of the cave (X:285, Y:-165). This area is guarded by two wolves and several Zhentarim operatives.

Within this restricted zone, there are two locked chests. The chest on the right contains a piece of Infernal Iron. If players have helped the Zhentarim by completing the "Find the Missing Shipment" quest, they may find it easier to navigate the hideout, but the storage area itself remains off-limits. Picking the lock while obscured by magical darkness or fog is a common strategy for obtaining this piece without turning the entire faction hostile.

Grymforge and the Infernal Alloy

While exploring the Underdark, players will reach Grymforge. Here, an NPC named Stonemason Kith (X:-662, Y:375) offers a unique opportunity. Kith is an investigator of ancient architecture. By engaging him in conversation and passing a series of checks—History, Investigation, and Perception—he will reward the player’s insights with a piece of Infernal Alloy.

Infernal Alloy functions identically to Infernal Iron for the purposes of Karlach’s quest and Dammon’s crafting. In fact, Dammon can use this single piece of alloy to forge multiple pieces of the Flawed Helldusk set simultaneously, making it one of the most efficient items to acquire in the early game.

Infernal Iron Locations in Act 2

As the story moves into the Shadow-Cursed Lands, the availability of Infernal Iron increases, though the environment becomes significantly more hazardous.

The Reithwin Mason’s Guild

Located in the town of Reithwin, the Mason’s Guild is a site steeped in the history of the Ketheric Thorm era. On the ground floor of the guild hall (X:-105, Y:18), a piece of Infernal Iron is simply sitting on a workbench. Unlike other locations, this piece does not require complex lockpicking or boss fights to obtain, though the surrounding area is populated by Shadows and Wraiths that can ambush unsuspecting explorers.

The Gauntlet of Shar: Balthazar’s Vault

During the exploration of the Gauntlet of Shar, players will encounter the necromancer Balthazar. Near his laboratory is a vault room containing several opulent chests (X:-821, Y:-752). One of these chests contains what is labeled as "Infernal Metal." Despite the slight name variation, this functions exactly like Infernal Iron. Opening the vault requires a high Sleight of Hand check, or the key can sometimes be found in the adjacent rooms if the player chooses to eliminate Balthazar’s undead sentries.

Yurgir the Orthon

Also within the Gauntlet of Shar is Yurgir, a powerful Orthon bound by a contract with Raphael (X:-647, Y:-758). Defeating Yurgir in combat is a significant challenge due to his invisibility and the explosive mines his displacer beast helps him deploy. Upon his defeat, players can loot a piece of Infernal Metal from his remains. For those who prefer non-combat solutions, it is possible to use persuasion or insight to convince Yurgir to eliminate himself or his followers, which still allows access to the loot.

Infernal Iron Locations in Act 3

By the time players reach Baldur’s Gate, Infernal Iron becomes more common, often dropped by the city's mechanized protectors.

Flymm Cargo Basement

In the Lower City, Flymm Cargo is a warehouse located near the docks (X:-1078, Y:312). The basement of this facility is involved in several major plot threads. On the floor near some crates, players can find a piece of Infernal Iron. The basement is guarded by Worgs, so players should be prepared for a brief skirmish upon entry.

The Steel Watchers

The Steel Watchers that patrol the streets of Baldur’s Gate and guard Gortash’s interests are powered by infernal technology. Almost every Steel Watcher has a chance to drop Infernal Iron upon destruction. While these enemies are formidable, their vulnerability to lightning damage makes them manageable for a well-prepared party. In the Steel Watch Foundry itself, larger quantities of Infernal Iron and the superior Enriched Infernal Iron can be found on tables or looted from the Hellfire Watchers.

The Iron Throne and Huido

Inside the Iron Throne underwater prison, a piece of metal can be found on a table in the submersible dock room at the very start of the escape sequence. Additionally, a merchant named Huido at the Grey Harbour docks sells Infernal Iron for approximately 1,000 gold. This price can be reduced or waived entirely depending on the player's class or successful dialogue checks.

Using Infernal Iron for Karlach’s Engine

The primary use for this metal is "The Hellion's Heart." This quest is divided into two major upgrades.

The First Upgrade

This typically occurs in Act 1 at the Emerald Grove. Providing Dammon with one piece of Infernal Iron allows him to perform a temporary fix on Karlach's engine. This upgrade grants her the "Heart of Iron" passive feature, which prevents her from being Charmed. More importantly, it allows her to safely channel her inner fire during rages without immediate risk of total engine failure.

The Second Upgrade

This occurs in Act 2 at the Last Light Inn. Dammon requires a second piece of Infernal Iron to further stabilize the engine. This upgrade is a turning point for Karlach’s character arc, as it allows her to physically touch others again without burning them. This is a mandatory step for players seeking to romance her. Mechanically, it replaces "Heart of Iron" with "Heart Ablaze," further enhancing her combat capabilities with fire-based utility.

Crafting the Flawed Helldusk Armor Set

Once Karlach’s engine is stabilized, any surplus Infernal Iron can be given to Dammon at the Last Light Inn to craft the Flawed Helldusk set. This heavy armor set is widely considered one of the best options available in the middle stages of the game.

  1. Flawed Helldusk Armour: This heavy plate armor offers a high AC and a unique reactive property. When a creature hits the wearer within 2 meters, the attacker potentially takes 1d4 Fire damage. It also reduces all incoming damage by 2.
  2. Flawed Helldusk Gloves: These add 1d4 Fire damage to weapon attacks and 1d4 Necrotic damage to unarmed strikes. They also grant a chance to inflict Bleeding on targets when using weapon actions.
  3. Flawed Helldusk Helmet: This piece provides a +2 bonus to Saving Throws against spells and prevents the wearer from being Critically Hit. It also includes a magical durability bonus.

Each piece of the set requires one piece of Infernal Iron. It is recommended to prioritize the gloves or the chest piece depending on whether the party needs offensive scaling or defensive stability. Note that in Act 3, Dammon can use Enriched Infernal Iron to craft even more powerful versions, but the standard "Flawed" set remains relevant for a significant portion of the game.

Strategic Considerations and Tips

Managing your Infernal Iron supply requires some foresight. While there are more than enough pieces in the game to complete Karlach’s quest and craft the full armor set, players can easily miss early opportunities.

Inventory Management

A common issue players face is the game failing to recognize Infernal Iron during dialogue with Dammon. This usually happens if the iron is stored in the Camp Chest or in the inventory of a companion who is not currently in the active party. To ensure the dialogue triggers correctly, place all pieces of Infernal Iron in the main protagonist's inventory before speaking to Dammon.

The Importance of Long Resting

Quest progression for Karlach can sometimes feel "stuck." This is often due to the game's event queue being backed up. If you have the iron and Dammon is available but the option to upgrade doesn't appear, try taking a Long Rest. This allows camp scenes and quest flags to reset, often clearing the path for the next stage of the engine repair.

Prioritizing Early Pieces

The pieces in the Blighted Village and the Zhentarim Hideout are the most important to secure early. If you progress too far into the goblin conflict—specifically by killing the leaders or siding with Minthara—the Zhentarim might relocate or become hostile, and the Emerald Grove might become inaccessible. Secure these pieces as soon as you are strong enough to handle the traps and minor combat encounters involved.

Common Troubleshooting

Players frequently report being unable to find Dammon in Act 2 or Act 3. This is almost always tied to the resolution of the "Save the Refugees" quest in Act 1. If the tieflings are forced to leave the grove without the goblin leaders being defeated, many of them, including Dammon, may not survive the journey to the Shadow-Cursed Lands. Furthermore, if the protection at Last Light Inn fails and the NPCs are turned into shadows, Dammon will become a hostile undead, effectively ending his role as a blacksmith.

For those who find themselves with an abundance of Infernal Iron in Act 3 but no Dammon, the metal can still be sold for a decent amount of gold (100gp base), though this is a poor use of such a rare resource.

In summary, Infernal Iron is a vital resource that bridges the gap between narrative progression and mechanical power. Whether you are driven by the desire to see Karlach find peace or the need to clad your frontline fighters in hell-forged plate, keeping a checklist of these locations will ensure you never fall behind in the arms race against the Absolute.