I’m a long-time Baldur’s Gate 3 player and I’ve helped dozens of friends save Karlach — here’s a clear, simple guide from someone who’s actually done the work. I speak plainly, I’ve noticed what’s easy to miss, and I’ll tell you why each step matters. (Author: woman, veteran player.)
Infernal Iron repairs Karlach’s infernal engine. You’ll need it to stop her engine from overheating and to unlock deeper scenes with her. This material is rare, usually found where smithing or infernal things appear. In my experience, you only need two pieces to progress her core quest, but more pieces improve outcomes and dialogue. There are exceptions depending on your playthrough and patch; check your save often.
Quick fact — why it matters
Karlach’s engine will harm her if left unchecked. That’s the simple reason to hunt this metal. Dammon, a tiefling blacksmith, can install upgrades that stabilize the engine and let you touch Karlach without her burning you. We found those upgrades matter for romance and certain endings.
Act 1: the most reliable spots 🔥
Act 1 holds the easiest pieces. I list the places I found on multiple runs and what to do there.
| Location | Area | How to get it |
|---|---|---|
| Blighted Village | Blacksmith’s basement | Pick the lock or use a key; chest inside |
| Goblin Camp | Shattered Sanctum | Loot from Dror Ragzlin or take during combat |
| Underdark (Grymforge area) | Near the rothe pits | Locked chest by mining gear; search carefully |
Short tip: use the highlight key often. It catches containers you’ll miss.
Act 2 spots we found
Act 2 gives fewer obvious pieces, but they’re meaningful. Check shadow-themed locations and any labs or forges. Specifically inspect Reithwin’s Mason’s Guild and containers in Gauntlet areas. One of my runs required backtracking — so save before major decisions!
How to apply Infernal Iron
Find Dammon and talk while the pieces are in your inventory. In my playthroughs he’s at the Emerald Grove in Act 1 and later at Last Light Inn in Act 2 — but that depends on story events and survival. If Dammon dies, you can’t get the upgrades (this doesn’t always work out the same way for every player). Why? He’s the only NPC shown able to work that metal, and the game treats the upgrades as scripted interactions, not craftable recipes you can DIY.
Upgrade effects — why they matter
- First upgrade: stabilizes the engine; physical contact becomes safe (huge for roleplay).
- Second upgrade: further stabilizes and opens more romance scenes.
- Third upgrade (if available): best ending quality for Karlach.
Why these upgrades matter: they change NPC flags and dialogue checks. Think of them like fixing a ship’s hull before a storm — the small fix prevents much bigger loss later.
Practical tips and caveats
Honestly, you’ll miss pieces if you rush. I’ve noticed people skip basements and locked doors — don’t. Here’s what I recommend and why:
- Bring a thief or someone with Thieves’ Tools. Locks block more than treasure; they block story access.
- Keep Detect Magic ready to spot magical containers — it helps find hidden stashes.
- Save before major choices that change settlements (Emerald Grove, Last Light Inn). You’ll thank me later.
Also: vendors sometimes sell rare parts, but that depends on your game state and who survives. There are exceptions (certain NPC deaths remove vendor stock).
Short checklist (copyable)
✔ Search blacksmith basements
✔ Check forges and smithing gear
✔ Loot goblin leaders and locked chests
✔ Talk to Dammon with pieces in inventory
✔ Save before settlement decisions
One odd and counterintuitive insight
Oddly enough, letting one early conflict slide can make it easier to get Dammon to Act 2 — sometimes avoiding a fight keeps him alive. It feels wrong, but it worked for me. Controversial? Yes, some players will argue you should “fight everything” — I disagree. Let’s be blunt: kill-everything playthroughs won’t always get the best emotional outcomes for companions.
Between us, romance choices aren’t just flavor. They change access to scenes and sometimes items. To be fair, romance isn’t required to finish Karlach’s arc, but it enriches it.
Final practical warnings
Protect Dammon. Protect the Grove or the Last Light Inn when possible. If you lose access to the smith, the quest can stall. Save often. Patch updates can alter vendor stock and NPC locations — as of 2025-11-25 this guide matches my runs and community reports, but check in-game if something looks different.
Want one blunt opinion? Saving everything isn’t always worth the time — prioritize the smith and Karlach’s scenes if you care about her. Surprising, I know, but sometimes focused play gives better story payoffs.
Good luck. Ask me where you’re stuck and I’ll point to the exact chest or door (I’ve played the routes enough to remember most of them!).
