The Cave

⛏️ Dig. Explore. Loot. Survive.

The Cave is a large underground exploration and survival scenario for Factorio 2.0 and Space Age.

Dig through solid rock, uncover hidden caverns, discover valuable loot, fight dangerous enemies, earn Coins, trade at the Market, and push deeper into the underground where every layer becomes more rewarding — and more dangerous.

Inspired by Diggy, rebuilt and expanded into a full progression-focused underground experience.

Why Play The Cave?

The Cave turns the underground into a complete gameplay path:

• Explore a huge diggable underground world
• Discover hidden treasure rooms and special caverns
• Fight enemies that scale with depth
• Earn Coins from combat and exploration
• Spend Coins at a central Market
• Unlock powerful rewards through underground progression
• Customize difficulty, research cost, storage, solar power and logistics
• Play with or without Space Age
• Fully multiplayer friendly

This is not just a mining mod.
It is an underground survival, loot, economy and progression system.

Underground Progression

The underground is divided into depth-based difficulty zones:

• Easy
• Medium
• Hard
• Nightmare

The deeper you go, the stronger the enemies become.

But the deeper you go, the better the rewards become.

Early areas are safer and useful for starting out.
Harder zones contain stronger enemies, better treasure, advanced equipment and rare rewards.

Cavern Types

While digging, you can uncover many different underground locations:

• Treasure Caverns
• Resource Caverns
• Nuclear Caverns
• Infested Caverns
• Military Caches
• Boss Caverns
• Secret Reward Rooms

Some caverns are safe.
Some are rich.
Some are traps.

Every wall may hide something.

Coin Economy

Enemies can drop Coins when defeated.

Coins are real physical items:

• Pick them up
• Store them
• Trade them
• Drop them
• Share them with other players

Coins are used as the main underground currency and are fully multiplayer friendly.

Stronger enemies give better rewards, including enemies from Nauvis, Vulcanus and Gleba.

Smart Nest Coin System

The Cave includes an anti-farming Coin system.

Enemy nests contain a limited hidden Coin Value pool.
As enemies spawn, they carry part of that value with them.
Over time, the nest becomes depleted.

Depleted nests can still spawn enemies, but they no longer generate infinite Coins.

This keeps combat rewarding while preventing permanent Coin farms.

Players are encouraged to explore deeper, search for valuable nests, and decide which nests are worth farming or destroying.

Central Market

Spend Coins at the Market to buy powerful progression rewards.

The Market can provide:

• Loaders
• Modules
• Robots
• Vehicles
• Tanks
• Spidertrons
• Power Armor
• Power Armor MK2
• Nuclear equipment
• Endgame personal equipment
• Advanced progression items

The Market allows players to progress through exploration, combat and survival — not only through standard factory production.

Treasure Progression

Treasure scales with depth.

Medium Depth

• Solar Panels
• Accumulators
• Robots
• Utility items
• Vehicles
• Early advanced rewards

Hard Depth

• Power Armor
• Tanks
• Nuclear components
• Stronger equipment
• High-value progression items

Nightmare Depth

• Spidertrons
• Power Armor MK2
• Portable Fusion Reactors
• Endgame equipment
• Rare high-value rewards

The deeper you explore, the better the loot becomes.

Permanent Underground Darkness

The underground is dark and dangerous.

The Cave includes solar configuration options so server owners and single-player worlds can decide how useful solar power should be underground:

• 25%
• 50%
• 75%
• 100%

This allows the underground to feel harsh, balanced, or more relaxed depending on your preferred playstyle.

Customizable Startup Settings

The Cave includes many startup settings so players and server hosts can shape the experience before starting a map.

Options include:

• Underground Difficulty Selection
• Research Level Difficulty
• Ore Patch Protection
• Solar Output Adjustment
• Chest Capacity Configuration
• Raw Ore Stack Size Settings
• Resource Level / Patch Size Settings
• Early Stack Size

You can make The Cave easier, harder, slower, faster, more vanilla, or more powerful depending on your world.

Research Level Difficulty

Choose how expensive research should be:

• Very Easy
• Easy
• Medium
• Hard
• Very Hard
• Marathon

This makes The Cave suitable for casual single-player worlds, co-op games and long-term multiplayer servers.

Equipment Grid Upgrade

The Cave adds an Equipment Grid Upgrade system.

Research upgrades that increase equipment grid size for:

• Modular Armor
• Power Armor
• Power Armor MK2
• Tank
• Spidertron

This gives armor, vehicles and Spidertrons a smoother long-term progression path.

Belt Compression & Early Stack Size

The Cave includes belt stacking and logistics progression.

Without Space Age

If Space Age is not active, The Cave provides its own Belt Compression system.

Players can unlock six Belt Compression research levels that increase belt stack capacity over time, up to a RedMew-inspired maximum of 80 items per belt stack.

This gives base-game worlds a powerful late-game logistics upgrade without requiring any external dependency mods.

With Space Age

If Space Age is active, The Cave works with the official Space Age belt stacking system.

The mod also includes an optional startup setting:

Early Stack Size

When enabled, Early Stack Size allows Space Age belt stacking progression to start earlier through:

• Inserter Capacity Bonus 7
• Stack Inserter
• Transport Belt Capacity 1
• Transport Belt Capacity 2
• Transport Belt Capacity 3
• Transport Belt Capacity 4

Transport Belt Capacity can progress up to stack size 6.

Inserters and item-output mining drills can benefit from early belt stacking.

Recipes, items, graphics and Space Age material requirements are not changed.

If Early Stack Size is disabled, the game returns to normal Factorio / Space Age behavior.

Space Age Support

The Cave supports Space Age and integrates underground progression with multiple planets:

• Nauvis
• Vulcanus
• Gleba
• Fulgora
• Aquilo

Planet-specific enemies, rewards, resources and progression systems are supported.

The Cave is designed to work alongside Space Age, not replace it.

Enemy Rewards

Enemies can drop Coins based on their danger level.

Supported enemy reward sources include:

Nauvis

• Biters
• Spitters
• Worms
• Spawners

Vulcanus

• Small Demolishers
• Medium Demolishers
• Big Demolishers

Gleba

• Wrigglers
• Strafers
• Stompers
• Gleba Nests

The stronger the enemy, the better the reward.

Ore Patch Protection

Optional startup setting.

Protect valuable resource patches from accidental construction.

Supports:

• Manual placement
• Blueprint placement
• Multiplayer gameplay

Invalid structures are automatically removed and refunded whenever possible.

Storage Customization

Configure the capacity of:

• Wooden Chests
• Iron Chests
• Steel Chests
• Logistic Chests

Useful for servers, long-term worlds and players who want stronger storage progression.

Controls & Tips

Use Backspace to clear underground cursors and markers.

This is useful if your screen becomes crowded while digging, exploring or marking underground areas.

Multiplayer Friendly

The Cave is designed with multiplayer in mind.

Coins, markets, rewards, digging, protection systems, progression settings and balance options are built to support shared multiplayer worlds.

Optional Mobile Base Integration

The Cave can be played normally by itself.

Players who enjoy mobile bases, vehicle interiors and portable factories may also combine it with compatible vehicle interior mods for an expanded exploration experience.

The Cave focuses on underground exploration and progression.
Mobile interiors can complement that by giving players a portable headquarters while they dig deeper.

Credits

Original Diggy scenario:
RedMew

Diggy Factorio 2.0:
bits-orio

Damage Indicator:
Dummiez

The Cave fork, Factorio 2.0 and Space Age updates, balancing, maintenance, bug fixes, multiplayer support, market system, progression systems and additional gameplay features:
behroozzx

Explore • Loot • Survive

Every wall may hide treasure.
Every cavern may hide danger.
Every expedition may lead to incredible rewards — or a quick death.

Good luck, Engineer.