What a datapack can change

NTM - Continuum keeps most of its numbers in datapack files instead of code. A datapack can add to them or change them without any Java, on all six targets. This page maps every folder HBM reads, says how copies from several packs combine, and lists what differs between Minecraft versions. To make a pack step by step, see Your first datapack.

HBM’s data folders

These folders are HBM’s own formats. They work the same on every target.

Folder or file	What it holds	Copies from several packs	Page
`recipe/<table>/`	Machine recipes (press, assembler, chemical plant and every other machine)	One file per recipe; top pack wins per id	Machine recipes
`recipe_removals/`	Recipes of any mod and any type to remove, by id	Every file applies	Removing recipes
`fluid_property/`	A fluid’s colour, temperature, hazard diamond and traits	Top pack wins, per fluid	Fluids
`fluid_property_patch/`	Changes to another mod’s fluid, without replacing its file	Every patch applies	Fluids
`value_maps/<registry>/`	Per-item, per-block, per-fluid, per-entity-type and per-material values (hazards, fuels, armor, parts)	Every pack’s copy merges	Data maps
`value_maps/patches/`	Changes to another mod’s data map	Applied after every copy	Data maps
`fallout_transform/`	What nuclear fallout turns blocks into	Top pack wins per file; files sorted by `priority`	Fallout transform
`item_pool/`	Weighted loot pools (structure loot, supply drops, vending machines, satellites)	Every pack’s copy merges	Item pools
`tags/`	Vanilla tags; HBM reads some of its own and many `c:` tags	Vanilla tag merging	Tags

Any recipe file, of any type, may also carry a top-level golem:requires list that ties it to an hbm.cfg switch. See Removing recipes.

Vanilla and loader data HBM ships

HBM also ships ordinary data in vanilla’s and the loaders’ formats. A datapack can replace these files with the usual vanilla rules (the top pack wins per file):

Folder	What HBM keeps there
`recipe/` (top level)	Crafting, smelting and other vanilla recipes. Remove them with a removal list.
`loot_table/blocks/`	Block drops.
`advancement/`	HBM’s advancements.
`damage_type/`	HBM’s damage types (death messages, exhaustion, scaling).
`jukebox_song/`	HBM’s music discs (26.1 and 1.21.1; 1.20.1 has no jukebox songs as data).
`worldgen/configured_feature/`, `worldgen/placed_feature/`	Ores, oil deposits, plants and other world features. Many placements also read `hbm.cfg` when a chunk generates.
`worldgen/structure/`, `worldgen/structure_set/`	HBM’s structures, so `/locate` finds them.
`worldgen/biome/`	The crater biomes.
`neoforge/biome_modifier/` (NeoForge), `forge/biome_modifier/` (Forge)	Which biomes get HBM’s features and mob spawns.
`neoforge/data_maps/item/furnace_fuels.json` (NeoForge only)	Furnace burn times of HBM’s fuels.

Points that are HBM-specific:

Which structure spawns in a region is drawn from the weights in hbm.cfg, not from the weight values in data/hbm/worldgen/structure_set/ntm_structures.json. Changing those weights in a datapack has no effect.
The biome tags hbm:has_structure/<structure> decide which biomes a structure may use, and the hbm:biome_dictionary/<type> tags tell HBM which 1.7 biome type a modded biome is. See Tags.
HBM’s NBT structure templates are read from the mod jar, not from data/*/structure/. A datapack cannot replace their contents.
Fabric has no biome modifier files: HBM adds the same features and spawns in code. On Fabric, change where a feature appears through the biome tags it uses (for example hbm:has_feature/foxglove) or by overriding its placed feature.
HBM’s extra loot in vanilla chests (dungeons, mineshafts and others) is added in code when the table loads. A datapack that replaces a vanilla chest table still gets HBM’s extra pool.

Folder layout

Put your files under your own namespace. Use data/hbm/... only for the folders that merge (HBM’s data maps and tags), or when you mean to replace one of HBM’s files; prefer the patch folders and removal lists for that.

Directorymy_pack/
- pack.mcmeta
- Directorydata/
  - Directorymypack/
    Directoryrecipe/ machine recipes (recipes/ on 1.20.1)
    Directorypress/
    my_plate.json
    Directoryrecipe_removals/
    removals.json
    Directoryfluid_property/ properties of the fluid mypack:<name>
    …
    Directoryfluid_property_patch/
    Directoryhbm/
    oil.json changes hbm:oil
    Directoryvalue_maps/
    Directorypatches/
    Directoryhbm/
    Directoryitem/
    hazards.json changes hbm:hazards
    Directoryfallout_transform/
    my_rules.json
    Directoryitem_pool/
    pool_supplies.json adds rows to POOL_SUPPLIES
  - Directoryhbm/
    Directoryvalue_maps/
    Directoryitem/
    hazards.json merges into hbm:hazards
  - Directoryc/
    Directorytags/
    Directoryitem/ tags/items/ on 1.20.1
    Directoryingots/
    uranium.json

Some folders take the file’s namespace from the thing it describes, others from you:

fluid_property/<path>.json under namespace ns describes the fluid ns:<path>. Water is data/minecraft/fluid_property/water.json.
A data map file sits under the map’s namespace (data/hbm/value_maps/item/hazards.json), and every pack’s copy is merged. A patch sits under your namespace.
An item pool’s name is the file name, in any namespace. data/mypack/item_pool/pool_supplies.json adds to HBM’s POOL_SUPPLIES.
fallout_transform/ and recipe_removals/ files can have any name in any namespace.
A machine recipe can sit in any subfolder of recipe/: its type (hbm:press) picks the table. Naming the subfolder after the table keeps ids readable (mypack:press/my_plate).

pack.mcmeta

The data pack format depends on the Minecraft version:

{
  "pack": {
    "description": "My HBM tweaks",
    "min_format": 101,
    "max_format": 101
  }
}

26.1 uses min_format and max_format instead of pack_format.

{
  "pack": {
    "description": "My HBM tweaks",
    "pack_format": 48
  }
}

{
  "pack": {
    "description": "My HBM tweaks",
    "pack_format": 15
  }
}

Version differences

Minecraft 1.21 renamed several vanilla data folders from plural to singular. HBM writes its data in the singular (26.1) form and its build renames the folders for 1.20.1. Your datapack must use the spelling of the version it runs on:

26.1 and 1.21.1	1.20.1
`recipe/`	`recipes/`
`loot_table/`	`loot_tables/`
`advancement/`	`advancements/`
`structure/`	`structures/`
`tags/block/`	`tags/blocks/`
`tags/item/`	`tags/items/`
`tags/fluid/`	`tags/fluids/`
`tags/entity_type/`	`tags/entity_types/`
`tags/game_event/`	`tags/game_events/`
`function/`	`functions/`
`predicate/`	`predicates/`
`item_modifier/`	`item_modifiers/`

This includes HBM’s machine recipes: on 1.20.1 they are read from data/<ns>/recipes/<table>/. The JSON inside is the same on every version.

Inside vanilla’s own files, some shapes differ too. HBM’s machine recipes, data maps and other HBM formats do not change:

	26.1	1.21.1	1.20.1
Crafting and smelting ingredient	`"minecraft:stick"`, `"#c:rods/wooden"`	`{"item": "minecraft:stick"}`, `{"tag": "c:rods/wooden"}`	as 1.21.1
Crafting result	`{"id": "hbm:ingot_steel", "count": 2}`	as 26.1	`{"item": "hbm:ingot_steel", "count": 2}`
Smelting result	`{"id": "hbm:ingot_steel"}`	as 26.1	`"hbm:ingot_steel"`
Extra item data	`components`	`components`	NBT `tag`
Biome modifiers	`neoforge/biome_modifier/` (NeoForge)	`neoforge/biome_modifier/` (NeoForge)	`forge/biome_modifier/` (Forge)

Fabric has no biome modifier files on any version. Load conditions (a file that loads only when another mod is present) are spelled differently by each loader; see Removing recipes.

HBM’s own folders keep their names on every version: value_maps, fluid_property, fluid_property_patch, fallout_transform, item_pool and recipe_removals. Tags inside them (such as #c:ingots/uranium in a data map) use the same spelling everywhere.

On 1.20.1 Forge the convention tag namespace is forge:, not c:. HBM still ships its c: tags there and also copies each of them to forge: with the same members. Its crafting recipes read the forge: copies; machine recipes and data maps keep reading c:. See Tags.

When changes apply

HBM reads all of these folders when the server starts and again on every /reload, and sends them to every client. You do not need to restart the game after editing a file. A file that fails to parse is skipped with a line in the log ([HBM] Skipped ... fluid property file(s), Data map hbm:hazards: skipping ..., Fallout transform file ... is broken), and the rest of the folder still loads. A broken recipe file is reported by the game’s own recipe loader.

Worldgen changes (features, structures, biomes, biome modifiers) only affect chunks generated after the world loads with them. /reload does not reload worldgen files: leave the world and open it again.

Settings that are not datapacks

Some of HBM’s behaviour is set in config files in the game’s config/ folder, not in datapacks. They apply to the whole game or server, and most are read at start-up:

File	What it holds
`config/hbm.cfg`	1.7’s main config: recipe modes (528 mode, LBSM, expensive mode), structure spawn weights, world generation rates, radiation and hazard switches.
`config/hbmConfig/hbmServer.json`	Server settings that `/ntmserver` lists and changes.
`config/hbmConfig/hbmClient.json`	Client display settings that `/ntmclient` lists and changes.
`config/hbmConfig/hbmMachines.json`	Per-machine numbers 1.7 made configurable.
`config/hbmConfig/hbmRadResist.json`	Per-item radiation resistance overrides. These win over the radiation_resistance data map. HBM writes `_hbmRadResist.json` as a template when the file is missing.
`config/hbmConfig/hbmCustomMachines.json`	Player-defined custom machines.