A number of file types exist for Minecraft, all for importing content. All Minecraft files are ZIP archives renamed to use a mc… extension. These archives can currently be divided into three sets:

• Levels (mcworld and mcproject): level data and associated resources for worlds and projects
• Assets (mcpack and mctemplate): cosmetics or supporting assets for worlds
• Composites (mcaddon and mceditoraddon): used to import up to one world or project and any number of asset types

All file types for Minecraft can be opened as any file, launching Minecraft and importing the content. When packages are imported, they are automatically unpacked into their constituent files and directories. If it was not already open, most file types will launch Minecraft in normal mode; mcproject and mceditoraddon will instead launch Minecraft into Editor mode.

Levels #

Levels represent save data and resources for regular worlds and Editor projects. All levels, regardless of mode, are imported to minecraftWorlds in the com.mojang directory.

Importing an exact duplicate of an existing saved level will create a duplicate saved level. Composite archives will only import one level if multiple are included, including across nested composite archives.

Worlds #

mcworld Archive encapsulating an individual world

World archives can be created a few different ways:

• Zipping the contents of a world directory and renaming the extension from zip to mcworld
• Using the "Export World" button on the Game settings screen for a world
• In Editor mode, exporting the world from the File → Export as → Playable world menu option. The world will be saved to the projectbackups directory in the com.mojang folder.
• In Editor mode, running the /project export world command. The world will be saved to the projectbackups directory in the com.mojang folder.

Importing a world package while Minecraft is launched in Editor mode will import the world as a project. The imported world will then be inaccessible outside Editor mode and will need to be re-exported as a world for playing. Editor extension packs bundled in a world archive will be retained on import outside Editor mode.

Projects #

mcproject Archive encapsulating an individual Editor project

Project archives can be created two different ways:

• Zipping the contents of a project directory and renaming the extension from zip to mcproject.
• Using the "Export Project" button on the Game settings screen for a world
• In Editor mode, running the /project export project command. The world will be saved to the projectbackups directory in the com.mojang folder.

If Minecraft is not open, launching a mcproject file will open Editor mode. Importing a mcproject will fail if Minecraft is open but not in Editor mode.

Assets #

Asset archives represent a singular instance of a number of non-level contents:

• Behavior packs
• Resource packs
• Skin packs
• World templates

All asset archives include a manifest describing their contents. An asset archive will fail to import if its manifest UUID and version exactly matches an existing asset archive of the same type. Note that behavior and resource packs share the same UUID/version space. Behavior and resource packs self-contained within a world, project, or template will not count as duplicates for the sake of importing.

Both asset extensions, mcpack and mctemplate, appear to functionally behave the same. It's best practice to use mcpack for behavior, resource, and skin packs and mctemplate for world templates to make it more clear what's being installed. Any number of asset archives may be included in a composite archive.

Packs #

mcpack Package representing an individual behavior pack, resource pack, skin pack, or world template. It's recommended only to use mctemplate for behavior packs, resource packs, or skin packs.

Packs are only created manually, by zipping the contents of a behavior pack, resource pack, or skin pack directory and renaming the extension from zip to mcpack. Behavior and resource packs are installed globally and do not conflict with matching behavior or resource packs installed in worlds, projects, or templates.

Behavior Packs #

Behavior packs are attached to servers to change or extend gameplay. Behavior packs are installed to the behavior_packs directory in the com.mojang folder.

Development behavior packs must be placed in the development_behavior_packs directory under com.mojang manually.

Resource Packs #

Resource packs are attached to clients to affect sounds, visuals, etc. Resource packs are installed to the resource_packs directory in the com.mojang folder.

Development resource packs must be placed in the development_resource_packs directory under com.mojang manually.

Skin Packs #

Skin packs are client-only packs for custom skins. Skin packs are installed to the skin_packs directory in the com.mojang folder.

Development skin packs must be placed in the development_skin_packs directory under com.mojang manually, but this feature appears non-functional.

World Templates #

mctemplate Package representing an individual behavior pack, resource pack, skin pack, or world template. It's recommended only to use mctemplate for world templates.

World templates are installed to the world_templates directory under com.mojang. World templates can be constructed in a few different ways:

• Zipping the contents of a world directory, adding a world template manifest, and renaming the extension from zip to mctemplate
• In Editor mode, using the "Export Template" button on the Game settings screen for a world
• In Editor mode, running the /project export template command. The world will be saved to the projectbackups directory in the com.mojang folder.

Composites #

Composite archives are used to import up to one level archive and any number or combination of asset archives in a single import action. In general, contents to a composite must be packaged. Directories can also be given on the top level of a composite archive for importing asset types (behavior packs, resource packs, skin packs, and world templates) without needing to pre-package them. Nested sub-directories for organization may not be used.

Composite contents are treated as usual. For example, importing a mcaddon contianing a mcworld while in Editor mode will import the world as a project.

Composite archives may also contain any number or nesting of other composite archives, even across Minecraft modes. Nested composite archives cannot be used to get around the singular world import restriction.

Composites can only be constructed manually by zipping archives and asset types.

Add-Ons #

mcaddon Generic composite content archive

Importing a mcaddon package while Minecraft is launched in Editor mode will import any contained world as a project. The imported world will then be inaccessible outside Editor mode and will need to be re-exported as a world for playing. Asset types are imported as usual.

Editor Add-Ons #

mceditoraddon Composite content archive for Editor mode

If Minecraft is not open, launching a mcproject file will open Editor mode. Importing a mcproject will fail if Minecraft is open but not in Editor mode.