CombinedWorld

Dimensions are declared by the server owner, who must edit level.dat by hand to add them, since the mod does not create them in the game interface. A dimension named with the xxx:yyy form can be used as an overworld, a nether with a lit nether portal that leads to the matching dimension, or an end whose end portal sends players back to xxx:yyy overworld. Dimensions meant to use these functions need the matching suffix, and other names should be avoided.

Travel between dimensions in the same namespace keeps the player inventory unchanged, and most player properties are saved and loaded when switching. Saved data sits in a data/ItemStorage.dat file that holds everything the mod tracks. Commands show their arguments when run without one, which helps when working out the syntax.

CombinedWorld runs on the server only, so players join without installing anything. It is a Fabric mod for 1.20.4 – 26.3, with 18 release versions covered and the latest Fabric file 1.38 for 26.3, published 2026-09-22. The code is released under the CC0 1.0 Universal license, so it is open source. The documentation is outdated, and the latest version is described in the GitHub source.