Polar is a world format very similar to Slime, with the same advantages:
- Small file sizes (see SLIME_COMPARISON)
- Single file world
- Immutable (worlds do not save until explicitly requested)
- Store worlds wherever (whether as a file or in a database)
- Great for lobbies and game arenas
- Fast loading and saving
Polar is also a single plugin and so doesn't require a Paper fork or classloaders
Polar currently supports versions 26.3 - 1.21.11, and requires minimum Java 25
Polar was originally developed for Minestom! See the Minestom library here
Polar is not designed for large worlds!
Polar is most useful when the whole world is mostly within render distance. The entire world is held in memory as a trade-off to allow for faster loading. This means the size/number of worlds you can load depends on how much RAM you have available.
If you need large worlds, it's likely Anvil (the default world format) will be more useful.
Permission nodes are simply polarpaper.<subcommand>, for example: polarpaper.info for /polar info
polarpaper.use for the root command (/polar)
Polar provides a few custom gamerules that can be defined in the config:
| Name | Type | Description |
|---|---|---|
| blockPhysics | Boolean | Controls block placement/interaction rules |
| blockGravity | Boolean | Allow gravity blocks to fall (sand, gravel) |
| liquidPhysics | Boolean | Allow lava/water to flow |
| blockFade | Boolean | Controls block fading or disappearing (e.g. snow/ice melting, fire burning out, coral death, turtle eggs) |