Thermal Caves

The Thermal Caves is an underground cave biome added by Terralith. It is a warm, humid cave type with water-filled lakes, lava pools, dripstone ceilings and clay-covered floors. In Fear Nightfall, Thermal Caves is a common underground biome, and its mob list is dominated by horror creatures from Born in Chaos and other mods, so it is a place where a player meets the pack's monsters in large numbers.

The biome is almost entirely underground. Its surface share is 0.01% of land, while its share of the cave layer at y = -30 is 3.83%. It is entered from the same cave carvers as other underground biomes: the vanilla cave, canyon and extra underground carvers.

Description

Thermal Caves has a stone-based floor and ceiling. The floor is made of granite, diorite, andesite, stone, tuff, smooth basalt and blackstone, placed in noise-driven patches. The ceiling is mostly stone and dripstone blocks, with occasional magma blocks. Clay patches appear on both floors and ceilings, and the floor and ceiling surfaces use separate low and high variants, so the cave floor has several layers of rough, uneven ground.

Water is the main feature. Terralith's thermal lakes are filled with water rather than lava, and the biome's water is coloured #43e7d6. The biome also has spring water and spring lava sources, and vanilla lava lakes appear in both underground and surface positions. Underwater magma blocks are scattered on the floors of the lakes, below the ocean-floor threshold, so a lake floor can glow and burn. Sea pickles grow in the water, and small dripleaf plants grow on the clay near the lakes.

Fog is #c0d8ff, the sky colour is #78a7ff, and the ambient music is the vanilla dripstone caves track. The mood sound is the vanilla cave ambience, played every 6000 ticks.

Generation

Thermal Caves has a temperature of 0.8 and a downfall of 0.4, with rain as its precipitation. It generates in the cave layer of the overworld, so it is found wherever the cave carvers open up underground space, and it borders other cave biomes. Its share of the cave layer is 3.83% at y = -30, which makes it one of the more common cave types in the pack. Its surface share of 0.01% means it is almost never found on open land.

Thermal Caves is not one of the biomes that Fear Nightfall weights at 6 times normal. The pack's spreading rule for horror caves (Infested Caves, Frostfire Caves and Spider Nest) does not apply to it, so its share is set by Terralith's own weights. The biome is still horror-heavy in practice because of its monster list, described below.

Features

Thermal Caves adds several terrain and decoration features of its own:

• Lakes: water lakes are placed on the cave floor, using Terralith's thermal lake noise.
• Dripstone: dripstone ceilings with dripstone blocks and magma block patches.
• Clay: clay patches on floors and ceilings, with lichen clay, dripleaf clay and dripleaf water variants.
• Sea pickles and dripleaf: these grow in water and on clay, mostly around the lakes.
• Underwater magma: 250 to 255 attempts per chunk, placed below the ocean-floor line.
• Monster rooms: the vanilla monster room and deep monster room features can appear in this biome.
• Amethyst geodes: the vanilla amethyst geode feature is included.

The biome also shares the vanilla ore set. Iron, gold, copper, coal, redstone, lapis and diamond ore all generate, and gravel, granite, diorite and andesite pockets appear in the stone. The pack adds more ores to this biome: an infected diamond ore feature from Born in Chaos, black argillite, sulfur ore from Butchery, and mithril ore from Iron's Spells 'n Spellbooks. Wild flax and cave urns from Supplementaries and wild carrots and onions from Farmer's Delight also appear here.

Mobs and structures

The monster list is long. Vanilla spiders, skeletons, creepers, slimes and zombies are the most common monsters, with a weight of 95 or 100 each. Horror mobs make up most of the rest of the list. Dread Hound, Krampus, Restless Spirit and Bonescaller appear at lower weights, and rarer horror mobs such as Dark Vortex and Supreme Bonescaller appear rarely.

Ambient spawns are bats and coal golems. Water spawns are fish and glow squid, plus Corpse Fish. Slime golems also spawn here as monsters, at a weight of 25.

Thermal Caves contains 104 structures, from both vanilla and modded sets. Among the notable ones are the mineshaft from vanilla, the Crypt from Graveyard, and the Firewell from Born in Chaos. Many of the structures are small houses, camps, ruins and remnants from Terralith Underground Structures and other mods. Horror structures from the pack's sparse-structures set, including Graveyard and Born in Chaos structures, are placed about 30% closer together than normal, so they are common in the biome. See the table below for the full list.

Monster

Ambient

Underground Water Creature

Water Creature

Water Ambient

Structures (104)

Mineshaft, Ruined Portal, Stronghold, Trial Chambers, Shrine Combat Tier 1, Shrine Combat Tier 2, Shrine Combat Tier 3, Shrine Combat Tier 4, Shrine Combat Tier 5, Shrine Tower, Crypt, Bunker, Ruin Town, Wild Ruin, Firewell, Campsite, Fire Camp, Horse Campsite, Mine With Campsite, Barn, Duck, Haystack, Horse Pen, Shed, Wheat Grain Bin, Windmill, Wooden Wheat Farm, Floating Islands, Large Floating Island, Azelea House, Deepslate House, Diorite And Deepslate House, House, Lil House, Tall House, Warped House, Small Oak Lantern, Blue Stall, Cart, Cartographer Tower, Large Cart 1, Large Cart 2, Orange Stall, Pink Stall, Red Stall, Castle Ruins, Crystal, Log Ruin, Ruined Beacon, Small Ruin, Statue Ruins, Stone Pillars, Arena, Calcite House, Castle Ruin, Castle Tower, Diorite House, Large Tower, Nether Portal, Small Deepslate House, Small Oak House, Small Tower, White House, Leaf Hollow, Small Pond, Tree 1, Tree 2, Tree 3, Tree 4, Tree 5, Tree 6, Tree 7, Tree 8, Volcano, Diorite Tower, Large Warped Tower, Dead Tree Oak, Tree Monument, Bench, Cathedral, Gallows, Lamp Chest, Mushroom Pond, Paths, Pile, Railway, Small Oak Pond, Sunzi Gate, Villager Statue, Rare Well, Small Copper Well, Small Tower Well, Small Well, Stone Fountain, Well, Remnant Big Remnant 2, Remnant Big Remnant 3, Remnant Big Remnant, Remnant Bridge Remnant, Remnant Medium Remnant 2, Remnant Medium Remnant, Remnant Miner Hut, Remnant School Remnant, Road Sign

Tips

• Bring light and fire protection. Lava pools are placed in the cave alongside the water lakes.
• Sea pickles and dripleaf are safe to collect near the lakes, but the underwater magma burns anything that stands on it.
• Expect horror mobs in every dark corner. Keep weapons ready at night, and do not fight in the open when several monsters spawn at once.
• Thermal Caves is a good place to find ores, because it shares most of the vanilla ore set and the pack's additions.