Baldur’s Gate 3: How to beat Grym and get items from the Adamantine Forge in BG3

Here’s how to forge powerful magic items out of Mithral Ore

The Underdark in Baldur’s Gate 3 holds many secrets, but few are as cool as the Adamantine Forge that lies behind the dark fortress of Grymforge – or, indeed, as useful to an enterprising adventurer on the lookout for powerful magic items. You can forge for yourself two strong gear pieces by using the ancient forge, but you require special molds as well as Mithral Ore to make magic items there. There is also the issue of the forge’s guardian, Grym, who doesn’t exactly want you to use the forge, so defeating him is another challenge you must overcome.

It’s all well worth the effort, though, because the Adamantine items you can get are pretty sweet.

Grym's not happy about anyone touching the Adamantine Forge, so you'll need to get rid of him first / Larian Studios

This guide has everything you need to master the Adamantine Forge and will arm you with the knowledge of where to find Mithral Ore, which Adamantine items you can forge, how to use the Adamantine Forge, and how to beat Grym.

BG3: Where to find Mithral Ore

The previous inhabitants of Grymforge have mined out the area pretty cleanly, but there are two veins of Mithral Ore they forgot.

A vein of Mithral Ore can be found south of the Ancient Forge waypoint across the lava river / Larian Studios

Once you’ve unlocked the Underdark – Ancient Forge waypoint, turn towards the south where you can see a ruined bridge and some scaffolding. Be careful, as this area is guarded by suits of Animated Armor, both the melee and ranged variants. Once you have defeated them, go around the ruins and you’ll face a rocky area filled with lava. 

Hop across the lava river and you'll find a silvery vein of Mithral Ore with a HP bar / Larian Studios

On the rock wall in the distance, you’ll be able to spot a vein of Mithral Ore, which you can get to after hopping over the lava stream. A quick Eldritch Blast or some similar force will crush the vein and give you the ore.

A second vein of Mithral Ore can be found in this library location on the way to the forge itself / Larian Studios

A second forgotten vein can be found as you descend down to the forge proper. Turn left after making the jump down the broken stairs and you’ll see a sort of library area surrounded by fiery lava. There is another ambush here as you approach it, with a group of Magma Mephits trying to take you down. Take a note of their abilities, because you’ll have to face more of them later on. Once you have beaten this ambush, advance into the library area and get the second ore.

BG3: All forgeable Adamantine items

Mithral Ore alone doesn’t help you very much. You need special molds to be able to forge items. These plates can be found all over the ruined fortress, which you explored on the way towards the forge. Some are found on the ground, others in chests or on bodies. Since you’ll only have enough ore to get two items, it’s worth considering the question of what to get – we can’t really answer that question for you, because it depends on your party, so here are all the options:

• Scimitar Mould – Adamantine Scimitar: Rare, +1 Scimitar with Swift Hitter (imposes Reeling on targets for one turn on hits) and Lethal Weapon (ignores Slashing Resistance)
• Splint Mould – Adamantine Splint Armour: Very Rare, +2 Splint Armor (Heavy) with Intense Adamantine Backlash (imposes Reeling for three turns on attackers that hit you) that prevents attackers from landing Critical Hits.
• Longsword Mould – Adamantine Longsword: Rare, +1 Longsword with Versatile Hitter (imposes Reeling on targets for one/two turn(s) on hits when held one-/two-handed), Diamondsbane (hitting objects always results on a Critical Hit), and Lethal Weapon (ignores Slashing Resistance).
• Mace Mould – Adamantine Mace: Rare, +1 Mace with Swift Hitter (imposes Reeling on targets for one turn on hits), Diamondsbane (hitting objects always results on a Critical Hit) and Lethal Weapon (ignores Bludgeoning Resistance).
• Shield Mould – Adamantine Shield: Rare, +2 Shield that imposes Reeling for two turns on attackers missing an attack against you, prevents attackers from landing Critical Hits, and unlocks the Shield Bash reaction.
• Scale Mail Mould – Adamantine Scale Mail: Very Rare, +1 Scale Mail (Medium) with Adamantine Backlash (imposes Reeling for two turns on attackers that hit you) and prevents attackers from landing Critical Hits.

I opted for Adamantine Scale Mail to equip Shadowheart with. Unfortunately, I'm affected by a bug that doesn't let me use the forge for a second time / Larian Studios

In sheer item rarity, the two armor pieces you can forge from the Mithral Ore are the winners of the bunch – being immune to Critical Hits is bloody fantastic for any character. All items from the forge have ways of imposing Reeling on enemies, which reduces their attack rolls by one as long as they have that status. The melee weapons all can ignore certain types of Resistance, which is a great feature as well in some situations, but perhaps not as generally strong as the armors.

BG3: How to use the Adamantine Forge

Upon arriving at the forge, you’ll find several things you can interact with. The big round piece is the crucible. Here’s where you insert the Mithral Ore. The coffin-like structure in front of it is the place you put the mold of the equipment piece you want. No worries if you ever misclick, there is a lever right next to it to release the mold and switch it out.

The coffin-like structure holds the mold and will contain the finished item / Larian Studios

Insert the ore and the mold and then use the lever you find on one of the outer platforms. That’ll release the giant hammer above the forge and send the platform down. Here’s where things get hot: Locate the wheel next to a big valve on one of the outer platforms. That’s where you let in the lava needed to actually smelt down the Mithral Ore in the crucible and make your equipment.

If this is your first visit to the Adamantine Forge, this is the moment Grym reveals himself and challenges you to battle. In that case, wait before you let in the lava and read the boss guide below first. 

Only the lava is hot enough to smelt down the Mithral Ore and transform it into a shiny magic item / Larian Studios

If you’ve already dealt with Grym and are ready to proceed with your second item, repeat the steps above: Insert the right mold (or keep the old one in, if you want the same item again), insert Mithral Ore, unleash the lava flow, and pick up the item from where you put in the mold.

At the moment, many players can’t use the Adamantine Forge for a second time due to a bug. For some this is resolved on reloading, but for others the forge just doesn’t come online again, because the crucible can’t be clicked on for some reason. We’re hoping that a patch is going to fix that issue soon.

BG3: How to beat Grym

This is Grym and he's really angry because you woke him up from his slumber / Larian Studios

You’ll want to make a few preparations before this battle with Grym begins. You don’t need any specific equipment to deal with the construct. However, once you’ve reduced the boss to half of his HP, four Magma Mephits will join the battle and harass your characters.

This is why you should craft Elixirs of Fire Resistance for your party. You need Dragon Egg Mushrooms and any Salt to make these. The hellish creatures have lots of fire attacks and could set your characters alight, so making yourself unable to be burnt and giving yourself Fire Resistance, which halves all incoming Fire Damage, is a great move. One annoying attack you need to look out for is Heat Metal, which could make your characters drop their weapons.

This is the battle formation for the Grym fight: a sturdy and athletic character in the center, someone with crowd control or AoE on the left, and the rest ready to activate the devices / Larian Studios

The most important part of this battle is your formation. You’ll want one person on the crucible in the middle, preferably someone with a high jump range. Another character needs to be with the wheel activating the lava flow and a third party member needs to stay with the lever calling down the hammer onto the crucible. You can position a fourth party member opposite the wheel that controls the lava flow, as that’s where the Mephits will show up.

Grym is completely invulnerable to any kind of damage as long as he stands on solid ground. Only when he stands in lava are his defenses reduced enough so that you can damage him. Even so, he’s got so many resistances and immunities that it’s going to take a long while to whittle him down. It goes without saying that you must avoid at any cost to go into the lava yourself. Stick to the high ground.

The last character to attack Grym gets the Prime Target condition, triggering Grym to go after them / Larian Studios

Grym is the vengeful kind of construct, so he’s going to try and attack the last person that hit him. This is important and the key to our strategy for this battle, which is to lure Grym right next to the crucible, but still standing in lava, and then pull the lever to let the hammer crush him. You’ll halve his 300 HP with the first blow and end his reign of terror with the second.

Even Grym's gonna feel that one / Larian Studios

After the battle has begun, only attack Grym with the person on the crucible. Everyone should be in their respective positions and help the bait’s defenses. Grym is going to march over and attack the character on the crucible, so make sure they can tank a hit. Then disengage with the person on the crucible and jump to safety onto one of the platforms. Next you want to select the party member sticking by the lever to pull it. BAM! Grym will be knocked prone and the Mephits will join the fray. Have one person welcome them and keep them busy.

My Warlock welcomed the Mephits with a friendly Hunger of Hadar spell / Larian Studios

The trickiest part of the battle comes now as the lava flow will stop after a few turns and Grym is right on the crucible, where he’s invulnerable. You’ll need to bait him over to one side, get back a character on top of the crucible, reactivate the lava flow and lure Grym back through it into striking range of the hammer.

Grym still looks pretty good for being repeatedly squished by that giant hammer. Good for him! / Larian Studios

Grym drops the Grymskull Helm, which grants Fire Resistance, Hunter’s Mark, and prevents enemies from landing a Critical Hit on the wearer.

Our experiments have shown that Mithral Ore is the only thing you can smelt in the Adamantine Forge – if you’re looking for uses of Infernal Iron, then you’ll want to find Dammon in Act 2.