Minecraft Resource Pack Skill

What Is a Resource Pack?

A resource pack is a folder (or .zip) that overrides or adds Minecraft's visual and audio assets: textures, models, sounds, language files, and fonts. No Java or mod loader is required for those vanilla assets.

Routing Boundaries

• Use when: the deliverable is visual/audio assets (textures, models, sounds, fonts) in resource-pack format.
• Do not use when: the task requires gameplay logic or runtime behavior changes (use minecraft-datapack, minecraft-plugin-dev, or minecraft-modding).
• Do not use when: the task is server infrastructure/runtime administration (minecraft-server-admin).

Pack Metadata

Use legacy pack_format only for resource formats below 65 (through 1.21.8). Resource format 65 and later require both min_format and max_format; use [major, minor] for exact patch targeting, including .0 such as [84, 0]. An integer or [major] min_format means [major, 0]; an integer or [major] max_format permits every minor version on that major line. Do not write decimal JSON numbers. A legacy-only pack can use its integer pack_format alone. A range whose min_format includes a legacy format needs integer pack_format and supported_formats; do not include supported_formats for a modern-only range.

Directory Layout

my-pack/
├── pack.mcmeta
├── pack.png                   ← 64×64 icon (optional)
└── assets/
    └── minecraft/             ← override vanilla (or <namespace>/ for new packs)
        ├── models/
        │   ├── block/
        │   │   └── stone.json
        │   └── item/
        │       └── diamond_sword.json
        ├── items/              ← 1.21.4+ item model definitions
        │   └── diamond_sword.json
        ├── blockstates/
        │   └── stone.json
        ├── textures/
        │   ├── block/
        │   │   └── stone.png
        │   ├── item/
        │   │   └── diamond_sword.png
        │   ├── gui/
        │   │   └── sprites/
        │   │       └── my_sprite.png
        │   └── entity/
        │       └── zombie/
        │           └── zombie.png
        ├── sounds/
        │   └── custom/
        │       └── my_sound.ogg
        ├── sounds.json
        ├── font/
        │   └── default.json
        └── lang/
            └── en_us.json

Client-mod-specific files such as OptiFine CIT and Iris shader packs use their own formats. Read conditional assets before adding them.

pack.mcmeta

1.21.8 and earlier

{
  "pack": {
    "pack_format": 64,
    "description": "My Custom Resource Pack v1.0"
  }
}

1.21.9 / 1.21.10

{
  "pack": {
    "min_format": [69, 0],
    "max_format": [69, 0],
    "description": "My Custom Resource Pack v1.0"
  }
}

1.21.11

{
  "pack": {
    "min_format": [75, 0],
    "max_format": [75, 0],
    "description": "My Custom Resource Pack v1.0"
  }
}

26.2

{
  "pack": {
    "min_format": [88, 0],
    "max_format": [88, 0],
    "description": "My Custom Resource Pack v1.0"
  }
}

Block Models

assets/minecraft/models/block/my_cube.json

Full cube — all six faces use the same texture:

{
  "parent": "minecraft:block/cube_all",
  "textures": {
    "all": "minecraft:block/stone"
  }
}

Column block (like logs):

{
  "parent": "minecraft:block/cube_column",
  "textures": {
    "end": "mypack:block/my_pillar_top",
    "side": "mypack:block/my_pillar_side"
  }
}

Different sides:

{
  "parent": "minecraft:block/cube",
  "textures": {
    "up":    "mypack:block/my_block_top",
    "down":  "mypack:block/my_block_bottom",
    "north": "mypack:block/my_block_side",
    "south": "mypack:block/my_block_side",
    "east":  "mypack:block/my_block_side",
    "west":  "mypack:block/my_block_side",
    "particle": "mypack:block/my_block_side"
  }
}

Cross model (flowers, plants):

{
  "parent": "minecraft:block/cross",
  "textures": {
    "cross": "mypack:block/my_flower"
  }
}

Custom geometry (elements)

{
  "credit": "Custom model",
  "ambientocclusion": true,
  "textures": {
    "0": "mypack:block/panel",
    "particle": "mypack:block/panel"
  },
  "elements": [
    {
      "from": [0, 0, 7],
      "to": [16, 16, 9],
      "faces": {
        "north": { "texture": "#0", "uv": [0, 0, 16, 16] },
        "south": { "texture": "#0", "uv": [0, 0, 16, 16] }
      }
    }
  ],
  "display": {
    "thirdperson_righthand": {
      "rotation": [75, 45, 0],
      "translation": [0, 2.5, 0],
      "scale": [0.375, 0.375, 0.375]
    }
  }
}

from and to are in 1/16th block units (0–16). uv is [x1, y1, x2, y2] in 0–16 units.

Item Models

For 1.21.4 and later, use item definitions in assets/<namespace>/items/. For 1.21.3 and earlier, use the legacy model overrides array. Read conditional assets for the string-based current custom_model_data selector and the legacy numeric predicate; their values are not interchangeable.

Blockstate Definitions

Simple block (no variants)

{
  "variants": {
    "": { "model": "mypack:block/my_block" }
  }
}

Facing block (4 rotations)

{
  "variants": {
    "facing=north": { "model": "mypack:block/my_block" },
    "facing=south": { "model": "mypack:block/my_block",  "y": 180 },
    "facing=east":  { "model": "mypack:block/my_block",  "y": 90  },
    "facing=west":  { "model": "mypack:block/my_block",  "y": 270 }
  }
}

Random texture (multipart)

{
  "variants": {
    "": [
      { "model": "minecraft:block/grass_block",  "weight": 3 },
      { "model": "minecraft:block/grass_block_2" }
    ]
  }
}

Multipart (slabs, fences, walls)

{
  "multipart": [
    { "apply": { "model": "mypack:block/my_slab_bottom" }, "when": { "type": "bottom" } },
    { "apply": { "model": "mypack:block/my_slab_top"    }, "when": { "type": "top"    } },
    { "apply": { "model": "mypack:block/my_block"        }, "when": { "type": "double" } }
  ]
}

Textures

• Format: PNG, RGBA (32-bit)
• Standard block/item size: 16×16 px
• Textures can be larger (32×32, 64×64) — Minecraft scales them, but stick to powers of 2
• Animation requires height = N × width (e.g., 16×64 for 4 frames)
• Place block textures in assets/<namespace>/textures/block/
• Place item textures in assets/<namespace>/textures/item/
• All textures are referenced without the .png extension in JSON

Animated texture MCMETA

assets/minecraft/textures/block/fire_0.png.mcmeta:

{
  "animation": {
    "frametime": 2,
    "frames": [0, 1, 2, 3, 4, 5, 6, 7]
  }
}

If frames is omitted, all frames play sequentially. frametime is in game ticks (default 1).

GUI sprites (1.20.2+)

Place sprites at assets/minecraft/textures/gui/sprites/<category>/<name>.png. Reference them with <category>/<name> in code/JSON.

26.1 block-model texture entries

For 26.1, a block-model textures entry may remain a sprite string or use an object. The object must have a string sprite; force_translucent, when set, must be a boolean.

{
  "textures": {
    "all": {
      "sprite": "mypack:block/frosted_panel",
      "force_translucent": true
    }
  }
}

Both forms identify a sprite without .png. Use force_translucent only when the geometry must render in the translucent pass despite its sprite pixels.

Sounds

An event's namespace comes from the namespace containing sounds.json; a sound entry's name identifies the sound-file namespace. Sound files are Vorbis .ogg under assets/<namespace>/sounds/. Read conditional assets for a correct event example, aliases, sound-source selection, and replacement behavior.

Language Files

assets/minecraft/lang/en_us.json:

{
  "block.mypack.my_block": "My Custom Block",
  "item.mypack.my_item": "Magic Wand",
  "entity.mypack.my_mob": "Forest Guardian",
  "death.attack.mypack.laser": "%1$s was zapped by %2$s"
}

• Use the exact translation key format for your mod/datapack namespace
• File name is the locale code (e.g., fr_fr.json, de_de.json)
• Always provide en_us.json as the primary fallback

Fonts

Read conditional assets for bitmap provider layout and private-use icon guidance.

OptiFine and shaders

OptiFine CIT and Iris shader packs have client-mod-specific formats. Read conditional assets before adding either; they are not portable vanilla resource-pack features.

Installation

# Singleplayer: place in
~/.minecraft/resourcepacks/my-pack/
# or
~/.minecraft/resourcepacks/my-pack.zip

# Server-side (forces on clients):
# Set in server.properties:
resource-pack=https://example.com/my-pack.zip
resource-pack-sha1=<sha1 hash>
resource-pack-prompt={"text":"Required pack","color":"gold"}

Common Issues

Validator Script

Use the bundled validator script before shipping a resource-pack update:

Unbundled references to another namespace's models, textures, sounds, or fonts are warnings requiring runtime verification with the dependency present. Missing files in the current namespace fail; strict mode also fails unresolved warnings.

# Run from the installed skill directory (for example `.claude/skills/minecraft-resource-pack`):
./scripts/validate-resource-pack.sh --root /path/to/resource-pack

# Strict mode treats warnings as failures:
./scripts/validate-resource-pack.sh --root /path/to/resource-pack --strict

What it checks:

• JSON validity for pack.mcmeta and assets/**/*.json
• Legacy versus modern pack.mcmeta field shape, including integer, [major], and [major, minor] versions
• Model/blockstate/font/sounds references resolve to real files
• Current custom_model_data select cases use strings; 26.1 texture objects use a string sprite and optional boolean force_translucent
• Same-namespace type: "event" sound aliases name an event in that sounds.json
• Every *.png.mcmeta has a matching *.png

The validator cannot resolve a sound event owned by another namespace, or prove that a command or mod code invokes an event with the intended sound source. Those cases warn and require an exact-client runtime check.

References

• Mojang: Java Edition 1.21.4
• Mojang: Java Edition 1.21.9
• Mojang: Java Edition 26.1
• NeoForge 1.21.8: Sounds
• Misode's model viewer: https://misode.github.io/
• OptiFine CIT guide: https://optifine.readthedocs.io/cit.html