Instances

An instance is a self-contained game folder: its own version, its own mods, its own worlds, its own configuration and its own resolution. Anything you change in one is invisible to the others.

Why they exist

Without instances there is one mods folder, one config folder and one saves folder for every way you play. Adding a shader to your creative world's setup can break the modpack you are 40 hours into, because both are looking at the same files. Instances make that impossible rather than asking you to be careful.

What one contains

instances/main/
  minecraft/
    mods/         # jars, including the ones the launcher ships
    config/       # each mod's own settings
    saves/        # your worlds
    resourcepacks/ shaderpacks/ screenshots/
    options.txt   # keybinds, graphics, FOV — per instance
  versions/       # the client jar and its json for this instance
  libraries/      # symlinked or copied from the shared store
  natives/        # extracted per launch, replaced each time

Creating one

1. Open the Instances page and press New instance, or press the same button on the Home strip.
2. Give it a name, pick a Minecraft version, and optionally a note about what it is for.
3. The instance is created and selected. Install a loader from the version picker if you want mods.

Managing one

Manage on any instance card opens the editor, and everything in it saves with one button:

• Name — what the tiles and the sidebar call it.
• Icon — the launcher mark by default, or a picture of your own. A picture is copied into the launcher's own folder, so moving or deleting the original later does not break the icon.
• Accent colour — the tint behind the icon. This is what tells two instances apart at a glance in the sidebar.
• Version — change it, or install another alongside by creating a second instance.
• Memory override — leave it alone to follow the global value, or pin it for a heavy modpack.
• Resolution override — the windowed size this instance opens at, so a screenshot instance and a gameplay instance can differ.
• Join this server on launch — passes the address to the game as --server, so you land in its world menu rather than at the main menu.

The selected instance

One instance is selected at a time. That is the one the Home page's play button runs, the one the sidebar card shows, and the one the Mods, Logs and Servers pages follow. Selecting a different instance does not stop a running game — the launcher only runs one at a time, and a second instance's Play button shows that another one owns the window rather than pretending to start.

Duplicating and importing

To copy an instance, copy its folder while the launcher is closed and create an instance with the same name; the launcher adopts the folder it finds. That is also the way to bring a setup over from another machine: move the whole instances/<id> folder into the launcher's data directory and the instance appears.