Alex's Caves Wiki

Alex's Caves is an exploration and adventure mod that hides four huge, hand-crafted cave biomes deep beneath the Overworld. Each biome is a self-contained world with its own atmosphere, terrain, plants, blocks, treasures, and a full roster of custom creatures with unique AI, models, and animations.

The four cave biomes are the Magnetic Caves, the Primordial Caves, the Toxic Caves, and the Abyssal Chasm - joined by the eerie Forlorn Hollows and the sugary Candy Cavity. Every biome adds its own mobs, materials, weapons, tools, armor, food, and decorative blocks, so each one plays very differently.

Alex's Caves is a content mod and requires the Citadel library to run. Install a matching Citadel build alongside it or the game will not start. See the Citadel wiki.

1. Install a mod loader that matches this build (NeoForge for the latest versions).
2. Install Citadel. Alex's Caves has a hard dependency on the Citadel library - drop a matching Citadel jar into your mods folder too, or the game will crash on load.
3. Place both jars (Alex's Caves + Citadel) into .minecraft/mods.
4. Launch and explore. The new cave biomes generate underground across the Overworld. Dig down and look for the tell-tale signs of each biome - magnetic metal, prehistoric fossils, glowing nuclear waste, or a bottomless flooded chasm.
5. Bring gear. Each biome has its own hazards (radiation, deep-sea pressure, aggressive bosses), so read the biome sections below before diving in.

Every creature also has a spawn egg in the Creative inventory if you want to study a mob before hunting for its home biome.

A metallic cavern of galena ore, magnetized rails, and floating iron. Everything here reacts to magnetism.

Creatures: Magnetron (a towering magnetic golem), Ferrouslime (a metal slime), Boundroid, Teletor, Notor, and the Quarry Smasher.

What you get: magnetic ores and metals, the Galena Gauntlet and magnetic weapons that pull or push mobs and metal, plus decorative industrial blocks. Use magnetism to move metal blocks and traverse the cavern.

A lush prehistoric jungle-cave full of dinosaurs, fossils, and amber. The most iconic Alex's Caves biome.

Creatures: Tremorsaurus (a roaring tyrannosaur), Grottoceratops (a horned ceratopsian), Vallumraptor (a pack-hunting raptor), Subterranodon (a flying pterosaur), Relicheirus, and the massive sauropod Atlatitan. The biome boss is the Luxtructosaurus, and the world-ending Tremorzilla can be summoned as an endgame threat.

What you get: fossils and amber (which can preserve items and mobs), limestone building blocks, Dinosaur Nuggets (a food), and prehistoric spears (Limestone Spear, Extinction Spear).

A radioactive wasteland of nuclear waste, uranium, and glowing hazards. Radiation will hurt you without protection.

Creatures: the Nucleeper (a nuclear creeper whose explosion is catastrophic), Radgill, Brainiac, and the Gammaroach (radioactive roaches that appear in groups).

What you get: uranium and nuclear materials, the Nuclear Bomb and remote detonator, hazmat protection, and a range of glowing decorative blocks. Handle the Nucleeper with extreme care - defusing a Nuclear Bomb is its own achievement.

A bottomless flooded trench of bioluminescent life, sunken wrecks, and crushing dark water - home to an entire deep-sea civilization.

Creatures: the Deep One society (Deep One, Deep One Knight, Deep One Mage), the enormous Hullbreaker, Lanternfish, Sea Pig, Tripodfish, Gossamer Worm, Trilocaris, and the Mine Guardian.

What you get: a rideable Submarine, deep-sea weapons and tools, glowing abyssal blocks, and trade with the Deep Ones. Watch for depth charges and mine guardians while exploring the wrecks.

Forlorn Hollows - a dark, eldritch cave of dread. Creatures include the Watcher, the boss Forsaken, Vesper bats, Corrodent, Underzealot, and Gloomoth. It yields dark, cursed gear such as the Desolate Dagger and Dark Arrows.

Candy Cavity - a bright, sugary wonderland. Creatures include the Gummy Bear, Caniac (a candy-cane hound), Gumbeeper, Candicorn, Licowitch, Gum Worm, Caramel Cube, Sweetish Fish, and the Gingerbread Man. It yields candy blocks, sweet foods, and playful gear like the Candy Cane Hook and Sugar Staff.

Each biome supplies its own equipment tier, so your loadout tells the story of where you have been:

• Magnetic: Galena Gauntlet, magnetic weapons that manipulate metal and mobs.
• Primordial: Limestone Spear and Extinction Spear (throwable), amber-preserved trophies.
• Toxic: Nuclear Bomb + Remote Detonator, hazmat protection against radiation.
• Abyssal: deep-sea tools, the rideable Submarine, and pressure-ready gear.
• Forlorn: Desolate Dagger, Dark/Burrowing Arrows, cursed accessories.
• Candy: Candy Cane Hook (a grappling tool), Sugar Staff, Frostmint Spear.

Many items have special right-click abilities, so check their tooltips in-game.

Alex's Caves ships with server and client config files (generated in your config folder on first run):

• Server config - toggle and tune each cave biome's world-generation, spawn rates, whether specific mobs and bosses can spawn, and difficulty/danger options (for example nuclear explosion behavior).
• Client config - visual and audio options such as screen-shake, particle intensity, and ambience.

Edit the .toml files with the game closed, or use an in-game config screen if your loader provides one (the mod also appears in the Mods list with its version and homepage). The mod reads an online mod-compatibility list on startup to warn about known world-gen conflicts with other big biome mods.

• Game crashes on startup / "missing Citadel". Alex's Caves requires the Citadel library. Install a Citadel jar that matches your Minecraft version.
• I can't find the cave biomes. They generate underground and can be rare. Dig/branch-mine widely, or create a fresh world so the biomes generate in newly-loaded chunks.
• World-gen looks broken with another biome mod. Large cave/biome mods can conflict. Check the mod's startup warnings and the config to disable overlapping features.
• A mob won't spawn. Confirm its biome exists nearby and that its spawn toggle is enabled in the server config; some creatures (bosses) are summoned rather than naturally spawned.
• Radiation is hurting me. That is the Toxic Caves - craft and wear the hazmat protection before exploring.