Structures and Dungeons — Every Spawn, Its Enemies and Its Loot

How structures work

Structures spawn next to the drill and you explore them for loot and equipment. Their difficulty is deliberately uneven: some are safe scrap rooms, others will end your run.

Two spawn rules matter:

• The first Dungeon is guaranteed at 3 km.
• After that, a structure spawns roughly every 7 km, randomly chosen from the pool available at your depth.

So a run is not a straight line — it is a series of decisions about which rooms are worth the risk at your current gear level.

Main structures

The layer names map to depth ranges on the layers page: Grass is 0–10,000 m, Dirt 10,000–17,000 m, Stone follows, and Clay sits at 17,000–24,000 m. Crystal is 31,000–41,000 m.

The Mineshaft is a trap

Every structure above has a difficulty rating that roughly matches its contents — except the Mineshaft.

It is rated 🟨🟨, the same as Dungeon Level 2, but it contains Watchers. A Watcher has 500 HP, moves at 25 speed, deals instant-kill damage, and cannot be killed with normal weapons. It is also a mineshaft, so you are fighting in a confined space with ore scattered around you.

Treat a Dirt Layer Mineshaft as a four-square room regardless of its label. The enemies guide explains which enemies ignore standard weapons.

The Goblin’s Arena is the loot room

Five squares of difficulty, and worth it. The Arena contains Goblins, Goblin Brutes, Goblin Knights and Goblin Champions — and the Champion drops a full equipment set (Champion’s Helmet, Chest, Legs and Hammer).

If you need gear rather than Coins, this is the room. A Goblin King class build gets extra value here, since goblins sell for double.

The Vampire Mansion gates your gear

Vampires drop Golden Keys and Gold Bars, and the mansion’s chests are what those keys open. At 🟥🟥🟥🟥 it is the hardest Clay Layer content, and Clay is where the Void Clay Wall Boss waits — the wall that empties your fuel. If you are going to run the mansion, do it before the boss wall, not after.

Other structures

Furnace Post is easy to overlook and it gates a class upgrade: Miner Level 3 requires smelting 50 Iron Ore and 25 Gold Ore, and smelting only happens at a Furnace Post. A 10% spawn chance is why that upgrade takes longer than the ore count suggests.

Church spawns on a fixed schedule rather than a random roll — once every 300 km. It saves your items and equipment, which makes it a checkpoint. On a 100 km run you will not see one; on a long multi-hour descent, the Church is what stops a wipe from costing you everything.

Drill Crash is the freebie: three items and a single Goblin, usually early in a run.

What to run and when

A rough priority order that follows the difficulty curve:

1. Dungeon Level 1 (Grass) — always worth it. Scrap and a Chest, low risk.
2. Spider Tunnel (Dirt) — easy Chests. Spiders are 100 HP and slow to threaten a group.
3. Mineshaft (Dirt) — only with explosives or pickaxes, or a very coordinated group. Otherwise skip.
4. Dungeon Levels 2 and 3 (Stone) — Scrap and Chests with escalating enemies. Level 3 adds Mole Men at 2,000 HP and 30 damage.
5. Vampire Mansion (Clay) — go for Golden Keys, before the Clay boss wall.
6. Spider Dungeons and Goblin’s Arena (Crystal) — the endgame loot rooms. The Arena is the better reward per risk.

Chest tier determines the Core payout — Wooden 1x, Golden 2x, Diamond 5x, Void 10x — so deeper structures pay disproportionately better. The Cores guide covers the multiplier maths, and how to reach 100 KM is the run plan that sequences all of this.

If you are picking a class to run structures with, Tank redirects damage in the enclosed rooms and Healer keeps the party up — the best classes tier list compares both.