migration

Migration

Breaking changes only — things that make a JSON file that worked in one version behave differently or stop loading in the next. Everything additive lives in the CHANGELOG.

This page is incomplete. It currently covers 1.6.0, and the network protocol change in 1.3.0. Earlier-breaking changes need to be pulled out of the CHANGELOG.

1.6.0

cooking_time is now in seconds

Applies to smelting, blasting, smoking and campfire_cooking.

- "cooking_time": 200
+ "cooking_time": 10

Divide your old value by 20. A file left untouched cooks 20× slower than intended — 200 used to be the vanilla furnace default and is now three and a half minutes.

Decimals are accepted, so "cooking_time": 7.5 is valid.

requires_player_kill now defaults to false

  "mob_drops": {
    "entities": ["all"],
    "chance": 0.10,
+   "requires_player_kill": true
  }

It used to default to true. If your drops back are a server economy, declare it explicitly — otherwise a fall-damage or lava farm prints currency with no player involved. The parser warns when the field is left undeclared.

The check also changed meaning: it now asks whether a player damaged the mob recently, not whether a player landed the killing blow. A mob finished off by its own fall after a player hit it still counts.

affected_by_looting replaced by looting_mode

- "affected_by_looting": true
+ "looting_mode": "count"

- "affected_by_looting": false
+ "looting_mode": "none"

The new third value, "chance", raises the drop probability instead of the amount — vanilla uses one or the other, never both on the same drop. Default is "count".

1.3.0

Network protocol

1.3.0 clients cannot join pre-1.3.0 servers, and vice versa. Both sides must update together. Nothing to change in your JSON files.