OP Spelunker Opening

The OP Spelunker opening is a resource-first route for runs where prestige gives you enough starting gold to skip early damage. Instead of immediately breaking the mountain, open Spelunker’s Guild, buy Spelunkers, and let expeditions return while the mountain stays mostly intact. This farms mapping, mithril, dens, PP rolls, artifacts, and other expedition rewards before normal damage ramps.

The next step is not to add random damage everywhere. Add Ballistics Workshop and Harpoon Ballistas so most of your new damage pressure goes into dens and den rewards instead of racing the mountain down too early.

Quick Answer

Step	Action	Player Reason
1. Start with enough gold	Use this only after prestige/start bonuses can afford Spelunker's Guild quickly.	If opening Spelunkers takes too long, the normal Miner + Maw start is faster.
2. Delay mountain damage	Do not rush Miners, Demolition Shack, Flameworks, or cannon damage at the start.	Keeping damage low gives expeditions more time to return before the run advances.
3. Buy Spelunkers	Open Spelunker's Guild and buy Spelunkers.	Every return can improve mapping and roll useful resources.
4. Stack mapping	Prioritize Underground Mapping and return-speed support.	Mapping improves several later Spelunker and demolition payoffs.
5. Add den-focused damage	Open Ballistics Workshop and buy Harpoon Ballista.	Harpoons are better than broad mountain damage here because dens, veins, and artifacts are the goal.
6. Resume normal scaling	After the economy is stocked, branch into Best Builds based on what is blocking the run.	At that point you have resources, mapping, and den access to support a stronger main build.

Why It Works

Mechanic	Player Meaning
Expedition timer	Spelunkers return after a timer, not after mountain damage. More time before the mountain dies means more chances to collect expedition outcomes.
Underground Mapping	Each useful Spelunker cycle helps the mapping plan. Mapping directly matters for Underground Mapping and later supports Mapped Destruction.
Mithril routes	Mithril Divining, mithril expedition outcomes, and revealed Mithril Veins make this route good when mithril is the wall.
Den economy	Spelunkers can reveal dens, and dens feed artifacts, mithril, and progression. That is why Ballistics Workshop is the clean follow-up.
Low damage control	Underbuilding damage is useful only while expedition returns are worth more than a faster mountain clear. Once returns slow down, start killing efficiently again.

What Scales With Mapping

Page	How Mapping Helps
Underground Mapping	The core mapping upgrade; build this early in the strategy.
Mapped Destruction	Converts Underground Mapping into Demodwarf damage once the prestige and Powder Hall gates are solved.
Spelunking Returns	Shows why return outcomes matter: gold, mithril, dens, PP, soul, artifacts, injuries, and death all come through this system.
Demolition Build Guide	Explains when mapping is high enough that Mapped Destruction becomes a real multiplier instead of a trap purchase.
Den Damage	Mapping and den reveals matter most when you can actually clear the dens that appear.

Ballistics Follow-Up

Buy	Strategic Use
Harpoon Ballista	Adds the den-focused projectile line. This is the first damage you want after the AFK Spelunker phase.
Lubed Crank	Improves Harpoon cooldown so dens die faster without needing a broad mountain-damage branch.
Dwarven Precision	Helps Harpoons connect with dens instead of wasting shots.
Monster Bane	Adds den damage once Mithril Forging support is available.
Multi-shot	Scales the projectile package after you have enough Harpoons.
Flaming Bolt	Adds fire support if Flameworks is open and the run is pivoting toward fire scaling.

When To Stop AFKing

Stop Trigger	Next Move
Expedition returns are no longer changing the run	Start normal damage and clear the mountain.
Dens are visible but not dying	Add Ballistics upgrades before adding general mountain damage.
Mithril is still the wall	Mithril Divining, Mithril Forging, and den clears beat more idle time.
Workers are stuck injured/resting	Buy return-speed and safety support, or stop the opening and switch to the main build plan.
Ore piles are being reclaimed	Fix runner throughput before adding more damage.

Common Mistakes

Mistake	Fix
Trying this before you have enough starting gold.	Use the normal beginner route until prestige/start bonuses make Spelunker's Guild fast.
Adding broad damage too early.	The point is to buy time for expeditions. If you kill the mountain too quickly, the strategy loses its edge.
Ignoring Ballistics after the AFK phase.	Harpoons let the build cash in dens and veins instead of only progressing the main mountain.
Letting workers sit under injury/rest pressure forever.	AFK is useful only while returns are efficient. If the return loop slows down, pivot.
Buying Mapped Destruction before mapping is high.	Mapping first, Mapped Destruction later. The demolition guide has the breakpoints.