Hollowmere

Hollowmere opens a door into The Hallowlands, an eternal-autumn dimension built for Halloween without gore. Light is a resource and the dark has teeth: hostile creatures, fog that hides them, harvest and blood moons, and an optional Dread that punishes anyone who stays outside a lantern's reach.

The way in is a crypt-portal. Build the stone tomb from the guide book, set four ritual candles on its rim and light four fires in its 2×2 pit: the pit becomes the veil. Step in and you cross at once, arriving on your feet two blocks in front of the return tomb, and the return trip is free.

Inside there are 18 biomes. The cold half is the original ten: Pumpkin Moor, Corn Maze, Drowned Crypts, Ash Hills, Tall Bone Forest, Veil Mire, Lantern Lake, Scarecrow Graveyard, Amber Mirror Wood and Abandoned Fair. The warm half is new in 1.0.2: Reef Lantern, Kelp Forest, Mist Lake, Deep Marsh, Hollow Wood, Harvest Fields, Ash Moors and Autumn Village. Each has its own fog, flora, surface rules, fauna and sounds; the two open-sea biomes have underwater plants, water creatures and two structures on the seabed (a sunken ship and a tide shrine).

The world is dressed with 56 structures in 15 sets and 77 pieces: crypts, a drowned cathedral, an ossuary, a necropolis, a keeper lodge, a mill settlement, a lantern harbor, an amphitheatre, a mirror maze, an abandoned fair, a reed stilt house and more. 70 entities populate it: 48 creatures, 11 multi-phase bosses and, new in 1.0.2, 11 boss spectres.

Spectres: once you have defeated a boss, a weakened ghost of it can turn up now and then in the Hallowlands (about once every ten minutes by default, and never before you have beaten that boss). It looks like the boss but translucent, with mist around it and a quieter voice; it has half the boss's health and 60 % of its damage, only fights in melee and drops no unique loot. All of it is configurable.

Gear: three tool, weapon and armour sets (Lanternplate, Moonstone and Umbrite), redrawn in 1.0.2 with one shared, mirror-symmetric design language: swords, pickaxes, double-bit axes, shovels, hoes and four armour pieces each.

There are 207 blocks, 187 items, 96 worldgen features and 210 recipes. The audio is original: 211 OGG files with creature voices, water and land ambience and four music pieces, all built for this mod. Sound subtitles come in English, Spanish, French, Portuguese (Brazil) and German.

Hollowmere is meant to be spooky-cozy: 16×16 art, no gore, no shaders, no custom HUD. The config has safe defaults for servers. On Fabric it requires Fabric API; on NeoForge and Forge it needs nothing beyond the loader.

1.0.2 is a content update: the eight new biomes with their own plants, creatures and structures, three water structures, nine creatures with their own models and animations, boss spectres, a Minecraft 26.3 build, redrawn tools and armour, decoration, stairs, slabs, walls, fences, doors, buttons and more derived blocks, food, two potions, a relic, a collection to complete, water sounds, a fourth music piece and a louder, better-encoded soundtrack. The known limitations are listed at the end of this page. They are not hidden.

Installation

Minecraft	Loader	Java	Extra dependency
1.20 – 1.20.4	Fabric	17	Fabric API
1.20 – 1.20.1	Forge 46 – 47	17	None
1.21 – 1.21.1	Fabric	21	Fabric API
1.21 – 1.21.1	NeoForge 21.0 – 21.1	21	None
26.2	Fabric	25	Fabric API (full build)
26.2	NeoForge	25	None
26.3	Fabric	25	Fabric API (full build)

Each jar declares the range it was measured on: static linking against each version's mappings and a dedicated-server test on each version. There is no NeoForge build for 26.3 yet because NeoForge has not published one. Not supported yet: 1.20.5–1.20.6 and 1.21.2–1.21.11, where Mojang changed APIs the jars use; they are planned for 1.0.5.

1. Install the loader for your game version.
2. On Fabric, install Fabric API for your exact game version (the latest build for that version is fine). In 26.2 and 26.3, use the full Fabric API build: the standalone fabric-resource-loader-v1 module crashes at startup in 26.2.
3. On NeoForge or Forge, no extra mod is required.
4. Put the Hollowmere jar in the mods folder.
5. Install Hollowmere on both client and server. In single-player the integrated server uses the same jar.
6. Use Java 17 for 1.20.x, Java 21 for 1.21.x and Java 25 for 26.2 and 26.3.

Back up the world before adding or removing the mod. Removing Hollowmere from a world where The Hallowlands has already been generated prevents the world from loading: the world stores the dimension, and without the mod its data is missing.

Updating from 1.0.0 or 1.0.1: worlds open unchanged. Chunks that were already generated keep their old biome contents; only newly generated chunks get the new plants, creatures, structures and biome layout.

Configuration

config/hollowmere.json, reloaded in game with /hollowmere config reload:

• fog_enabled (true) and fog_density (0.35): biome fog.
• leaf_rain_enabled (true) and leaf_rain_density (0.5): falling leaves.
• dread_enabled (false), dread_damage (1.0) and dread_moon_scale (1.5): the optional Dread.
• darkness_seconds (0): extra darkness on entering the dark; 0 turns it off.
• harvest_moon_nights (3) and blood_moon_every (7): moon calendar.
• lantern_light (7): light level of the mod's lanterns.
• portal_sound (true) and accessible_audio (false): portal sounds and softer variants.
• settlement_growth (true) and transform_scale (1.0): village growth.
• spectre_enabled (true), spectre_probability (0.10, chance per minute), spectre_health_scale (0.5) and spectre_damage_scale (0.6): the boss spectres.

Commands: /hollowmere portal_coords, /hollowmere verify, /hollowmere config reload.

Known issues and pending work

These are the player-facing limitations at the 1.0.2 cut. They are listed here so nobody has to discover them after installing.

1. The open-sea biomes have only two structures. Reef Lantern and Kelp Forest get the Sunken Hull and the Tide Shrine, which rest on the seabed; the other six new biomes have land and lake structures, but the crafts-folk towns (woodcutter, noble, witch, gleaner, ferryman, carver) still appear only in their original biomes.
2. The new biomes reuse plants and trees of their sister biomes. Each mixes them in its own way, but they have no trees of their own yet.
3. Drowned Crypts and Veil Mire can look sparser than other biomes. Much of both biomes is open water. Chunks generated before 1.0.1 keep their old vegetation.
4. A few ember ore blocks can appear in Veil Mire. It is a biome-border effect of ore veins; it does not block progression.
5. Minecraft 1.20.5–1.20.6 and 1.21.2–1.21.11 are not supported yet, and there is no NeoForge build for 26.3. All seven jars were opened in a real game client and joined a server. The 26.3 jar was only looked at in game (its window does not take scripted keys); the full in-game walkthrough was done on 1.20.1, 1.21.1 and 26.2.
6. Custom particle types (falling leaves, embers, fireflies) are planned for 1.0.5; the leaf rain uses vanilla particles tinted per biome.
7. Translations: only English and Spanish are complete. French, Portuguese (Brazil) and German cover the sound subtitles only and were not reviewed by native speakers; the rest of the text falls back to English.

Accessibility and photosensitivity

Hollowmere contains brief light flashes used as attack warnings (capped at three per second), sudden darkness during some boss phases, short Blindness and Nausea effects, biome fog and ambient particles. Fog, leaf rain and the optional Dread can be disabled in config/hollowmere.json, and accessible_audio replaces the portal and candle sounds with softer variants. The boss darkness phases are part of the fight and are not configurable in 1.0.2.

If you are sensitive to flashing lights, sudden darkness, fog or screen distortion, play in a well-lit room and in short sessions, and skip the boss fights you are not comfortable with.

Disclosures

AI assistance. Hollowmere was made with AI assistance under the author's direction, and everything was reviewed before release. By area:

• Code: written with AI assistance.
• Textures and icons: drawn pixel by pixel by the author's own scripts (Python with Pillow), not by an image-generation model. The scripts themselves were written with AI assistance.
• Models and blockstates: generated by the author's own scripts from the block and creature definitions.
• Audio: none of it is AI-generated. The music (four pieces), the ambience (nine loops and the occasional sounds, including the new water ones), the portal and candle sounds and the voices of seven wildlife creatures are synthesised from scratch by the author's own code. The other creature voices and the boss ability sounds are built from 55 licensed recordings (see Credits), edited, pitched, layered and mixed.
• Text: the descriptions, the in-game texts, the documentation and the sound subtitles (including the French, Portuguese and German ones) were written with AI assistance.

No generative AI runs inside the mod, and the mod sends no data anywhere.

No telemetry, no ads, no paid features. The mod does not collect or send data, does not contain advertisements and has no paid unlocks. Outside the world save, it only reads and writes its own config file inside the game directory. It is MIT licensed and fully free.

Credits

Author, code, art, data and audio direction: FernWork.

Audio: the creature voices and the boss ability sounds were built for Hollowmere from 55 licensed recordings, then edited, pitched, layered and mixed. The music, the ambience and the portal and candle sounds are synthesised by code. Attribution-required sources:

• erdie — Pig grunt — Wikimedia Commons — CC BY 3.0
• Shizhao — Bear growl — Wikimedia Commons — CC BY 3.0
• Briefer et al. (Scientific Reports) — Horse whinnies — Wikimedia Commons — CC BY 4.0
• Faragó et al. — Dog growls — Wikimedia Commons — CC BY 2.5
• SwampVids — American Toad Vocalization — Wikimedia Commons — CC BY 4.0
• Yannick Dauby — Bat echolocation — Wikimedia Commons — CC BY 2.5

Tools: Fabric Loom, NeoForge ModDevGradle, ForgeGradle, Stonecutter, Gradle and JUnit.

Minecraft is a trademark of Mojang Studios and Microsoft. Hollowmere is not affiliated with or endorsed by Mojang or Microsoft. No Mojang assets are redistributed; the mod's textures and models are original.

License

Hollowmere is released under the MIT License. The full text is in LICENSE. You may use, modify, redistribute and include it in modpacks under the terms of that license. Copyright (c) 2026 FernWork.

The source code is not public.