What a Player Carries

A server that plays several game modes would otherwise give a player one inventory, one level and one set of advancements for all of them: a stack of diamonds walks from a classic island onto a fresh Boxed one, and a Boxed box never grows for an advancement earned somewhere else. So worlds fall into groups. A player who crosses from one group to another puts down what they carry in the group they leave and picks up what they had in the group they enter.

It is set in modules/player-state.conf.

Groups

groups {
    main = ["world"]
    boxed = ["boxed"]
    realms = ["realms"]
}

• Worlds in one group share what a player carries.
• Leave groups empty for a group of each world a preset makes islands in, so every game mode with a world of its own keeps its own.
• Every world belongs to exactly one group. A world no group names belongs to the group of the server's own island world, a lobby or a resource world as well, unless you name it in another group.
• In the Nether and the End every mode shares, a player carries for the island they stand over: over a Boxed island, their Boxed things.

What is kept apart

Each of these is true as shipped. Something switched off is carried everywhere.

enabled = false keeps nothing apart.

Safety

What is kept belongs to the player's profile and is written with its inventory, in one step, before the player is given anything. A crash on either side of a crossing leaves the profile whole: nothing is lost or had twice.