30-Second Quick-Start (TL;DR)
- Descend to the Cavern layer (deeper than the Underground layer)
- Equip a Life Form Analyzer to detect rare enemies
- Hunt for the Lost Girl NPC (extremely rare spawn)
- Attack or stay near the Lost Girl until she transforms into a Nymph
- Defeat the Nymph; she has a 50% chance to drop the Metal Detector
- Once obtained, equip the Metal Detector in an accessory slot
- The Metal Detector displays all valuable items nearby in text form on your screen
What This Guide Helps You Do
This guide teaches you how to locate, farm, and use the Metal Detector—a rare accessory that displays all nearby valuable items in real-time. You’ll be able to spot ore, gems, chests, and other loot without manually scanning the environment. It’s essential for efficient resource hunting in Terraria and works best for players in early-to-mid hardmode who want to optimize farming runs and never miss hidden valuables again.
Requirements & Prep
Essential Items:
- Life Form Analyzer (an accessory that displays rare enemy spawns and information)
- Decent combat gear to handle a Nymph (a hard-mode mob with respectable damage output)
- Healing items (potions for safety during the Nymph fight)
Location Requirements:
- Access to the Cavern layer (the deepest underground region, roughly 700+ blocks beneath the surface)
- Ability to traverse underground terrain safely
Route Overview
Finding the Metal Detector requires a specific hunt-and-capture approach. You’ll travel deep underground to the Cavern layer, use the Life Form Analyzer to scan for rare enemy spawns, and wait for the Lost Girl NPC to appear. She’s exceptionally rare, so patience is critical. Once she shows up, engage her in combat—attacking or staying near her will trigger her transformation into a Nymph, a harder-hitting variant. Defeat the Nymph, and there’s a 50% chance she’ll drop the Metal Detector. After obtaining it, simply equip it as an accessory, and it’ll begin displaying all nearby valuable items as text information on the right side of your screen.
Step-by-Step Walkthrough
Prepare Your Loadout and Head Underground
Before descending, equip the Life Form Analyzer in one of your accessory slots. This tool is non-negotiable for this hunt—it’ll show you rare enemy information and alert you when valuable creatures spawn nearby. Stock up on healing potions and make sure your combat gear is suitable for hard-mode enemies. Head to any underground entrance and begin your descent toward the Cavern layer.
Navigate to the Cavern Layer
Terraria’s underground is divided into zones. The surface is above ground, the Underground layer sits roughly 700 blocks below the surface, and the Cavern layer is even deeper. You need to reach the Cavern layer specifically—that’s where the Lost Girl spawns. Keep descending until you’re well below the Underground layer. The Life Form Analyzer will help confirm your depth and show you what creatures are around you.
Use the Life Form Analyzer to Scan for Rare Spawns
With the Life Form Analyzer equipped, check the information displayed on the right side of your screen. It’ll show you rare creatures in your vicinity. The Lost Girl is exceptionally rare—you may need to explore multiple Cavern areas or wait for extended periods. The analyzer will alert you when rare enemies appear, eliminating the need to hunt blindly. If you see “rare creatures” listed, you’re in an active spawn zone.
Locate and Identify the Lost Girl
Look for a slow-moving, humanoid figure in the Cavern—the Lost Girl has a distinct appearance that sets her apart from common enemies. She moves deliberately and looks visually different. The Life Form Analyzer will help confirm her presence. Finding her is the hardest part of this process due to her rarity; you may need to explore multiple Cavern areas or return multiple times.
Trigger the Lost Girl’s Transformation
Once you’ve found the Lost Girl, attack her or stay close to her. This interaction will trigger her transformation into a Nymph—a much more dangerous variant with the same visual design but significantly increased damage output. The Nymph is a hard-mode mob, so expect a moderately challenging fight. Be prepared to dodge and heal as needed.
Defeat the Nymph and Secure the Drop
Engage the Nymph in combat using your equipped weapons and items to whittle down her health while managing incoming damage. The fight is manageable with decent gear and healing items. Once defeated, there’s a 50% chance she’ll drop the Metal Detector. If she doesn’t, you’ll need to find another Lost Girl and repeat the process.
Equip and Test the Metal Detector
Once you’ve got the Metal Detector, place it in an accessory slot. It’ll immediately activate, displaying text information on the right side of your screen showing all valuable items within detection range. This includes ore, gems, chests, and other loot. You can now use this tool to optimize your mining and farming routes by knowing exactly where valuables are located before you dig.
Troubleshooting & Common Mistakes
- Can’t find the Lost Girl: The Lost Girl is extremely rare. Make sure you’re in the Cavern layer (deep underground) and that your Life Form Analyzer is equipped and active. Explore multiple areas and be patient—rare spawns can take time.
- Life Form Analyzer not showing information: Verify it’s equipped in an accessory slot. The tool must be actively worn to display rare enemy data.
- Lost Girl not transforming: Attack her or stay directly near her. The transformation is triggered by player interaction; passive proximity alone may not be enough.
- Nymph is too difficult: If you’re taking heavy damage, retreat and heal. Use ranged weapons to maintain distance, or switch to higher-defense gear. The Nymph is a hard-mode enemy, so farm better equipment first if you’re struggling.
- Nymph didn’t drop the Metal Detector: She has a 50% drop chance, so you may need to defeat multiple Nymphs. This requires finding more Lost Girls and repeating the process.
- Metal Detector not displaying items after equipping: Make sure it’s in an active accessory slot (not a vanity slot). The display appears as text on the right side of your screen and shows the most valuable items nearby.
Understanding the Metal Detector’s Function
Once equipped, the Metal Detector acts as a real-time resource scanner. It displays text-based information on the right side of your screen, listing the most valuable items within detection range. This includes ores, gems, crystals, and other loot. The detector automatically prioritizes the most valuable finds, making it easy to spot high-value resources without manually exploring every tile. It’s particularly useful for mining routes, cave exploration, and dungeon runs where hidden chests and valuables are common.
Watch For: The Lost Girl is an exceptionally rare NPC spawn. Don’t expect to find one on your first trip to the Cavern layer. This hunt requires patience and multiple exploration sessions. The 50% drop rate on the Nymph also means you may need to repeat this process several times to secure the Metal Detector.
FAQ
Q: Where exactly is the Cavern layer?
A: The Cavern layer is the deepest underground zone in Terraria, located approximately 700+ blocks beneath the surface. It’s deeper than the standard Underground layer and is where the Lost Girl spawns.
Q: Can I find the Metal Detector anywhere else?
A: Based on this guide, you’ll get the Metal Detector exclusively from the Nymph (transformed Lost Girl) in the Cavern layer. There’s no other acquisition method mentioned.
Q: How rare is the Lost Girl spawn?
A: The Lost Girl is very rare, and you typically won’t find her easily. Exact spawn rates aren’t specified, but expect to spend considerable time hunting for her.
Q: What’s the difference between the Lost Girl and the Nymph?
A: The Lost Girl is the NPC form—slow-moving and passive. When attacked or approached, she transforms into a Nymph, which has the same appearance but deals significantly more damage and is a proper hard-mode combat encounter.
Q: What does the Metal Detector actually show me?
A: The Metal Detector displays text information on the right side of your screen, listing all available valuable items nearby. It prioritizes the most valuable finds, making it easy to spot ore, gems, chests, and other loot without manual searching.
Q: Is the Metal Detector worth the effort to farm?
A: Absolutely. The Metal Detector significantly speeds up resource gathering by eliminating blind mining and exploration. For players focused on farming, building, or progression, the convenience is well worth the hunt.
Quick Reference Card
- Goal: Obtain the Metal Detector from a Nymph (transformed Lost Girl) in the Cavern layer
- Key Tool: Life Form Analyzer (equip before descending)
- Location: Cavern layer (deepest underground zone, 700+ blocks down)
- Target Mob: Lost Girl → Nymph (triggered by attack or proximity)
- Drop Rate: 50% chance from defeated Nymph
- Rarity: Lost Girl spawn is extremely rare; expect multiple trips
- Equip Slot: Accessory slot (not vanity)
- Function: Displays valuable nearby items as text on screen (right side)
- Prep Items: Healing potions, combat gear, Life Form Analyzer
- Combat Difficulty: Nymph is a hard-mode mob; bring defensive gear and healing
- Time Investment: High (rare spawn hunt) but one-time reward with permanent benefit
- Payoff: Permanent resource detection for optimized farming and exploration
