Skip to main content
The three examples below are the actual files the mod copies into customadvancements/customadvancements/ on its first launch. They form a small, self-contained advancement tree: a root tab, a simple task child, and a reward-bearing task that chains off the second. Together they demonstrate every common pattern you will encounter when writing your own advancements. All three files belong to the customadvancements namespace. If you deleted them, recreating them in .minecraft/customadvancements/customadvancements/ will load them again on the next /ca reload.

​
1. Root Advancement — root.json

A root advancement defines an entirely new tab in the advancements screen. It has no parent field, and its display block must include a background to fill the tab panel. The minecraft:tick trigger fires every game tick, so the root completes silently the moment any player logs in.
root.json
Notable fields:
  • background — Points at the bundled screenshot.png in customadvancements/data/textures/. Required on every root advancement; a root without it fails validation and is skipped.
  • largeBackground: true — Switches on the mod’s own renderer so the image is drawn once across the whole panel instead of being tiled at 16×16 like a vanilla background.
  • shouldBgClip: true and bgRatio: 1.7208029197 — Keep the image’s real proportions and crop the overflow rather than stretching it. The ratio is the screenshot’s own width divided by its height. See Backgrounds.
  • show_toast: false and announce_to_chat: false — Root advancements that complete on every login should never fire notifications; these two flags suppress both the toast overlay and the chat broadcast.
  • minecraft:tick trigger — The simplest possible trigger. No conditions block is needed because the tick trigger always fires unconditionally.
  • No parent — This is what makes the advancement a root and gives it its own tab.

​
2. Simple Task — example.json

This is a standard child advancement linked to the root above. It completes as soon as dirt appears anywhere in the player’s inventory, triggering a toast and a chat announcement.
example.json
Notable fields:
  • parent: "customadvancements:root" — Links this advancement as a child of root.json. The resource location is the namespace (customadvancements) plus the file path without the .json extension (root).
  • frame: "task" — Renders the standard square frame around the icon. Use "goal" for a rounded frame or "challenge" for a star frame on more difficult objectives.
  • minecraft:inventory_changed trigger — Fires whenever the player’s inventory changes. The conditions.items array narrows it to only fire when at least one minecraft:dirt item is present.
  • No background — Child advancements do not own a tab, so the field would have no effect and is simply left out.
  • No requirements field — With only one criterion, omitting requirements means that single criterion must be satisfied, which is equivalent to [["requirement"]].

​
3. Task with Rewards — back_to_the_roots.json

This advancement chains off example.json and requires the player to kill an adult zombie while holding rotten flesh in their main hand. On completion it grants 50 experience points.
back_to_the_roots.json
Notable fields:
  • minecraft:player_killed_entity trigger — Fires when the player lands the killing blow on any entity.
  • conditions.entity — An array of condition objects the killed entity must match. The single entry here uses minecraft:entity_properties to assert that the entity is a minecraft:zombie and is not a baby (is_baby: false).
  • conditions.killing_blow — Inspects the damage source. The direct_entity.equipment.mainhand.items array requires the player to be holding minecraft:rotten_flesh in their main hand when the kill lands.
  • requirements — Explicitly lists the single criterion. With only one criterion this is optional, but it is good practice to include it for clarity.
  • rewards.experience: 50 — Awards 50 XP points directly to the player on completion. See Criteria for the other reward types.
  • Chained parent — Pointing at customadvancements:example rather than the root makes this a third level in the tree, so the player must work through example.json first if progression gating is enabled.

​
Translating the Example Tree

All three files use translate components rather than hardcoded strings, and the mod ships matching language files in customadvancements/data/lang/. The English one reads:
customadvancements/data/lang/en_us.json
German, Spanish, and French versions are copied in alongside it. See Language Files for the full guide.

​
Using Vanilla Advancements as Templates

Writing advancement JSON from scratch can be tedious when you are not sure what a complex conditions block should look like. The /ca generate advancement all command exports every currently loaded advancement — vanilla and mod alike — as ready-to-edit JSON files placed directly into customadvancements/, grouped by namespace.
This gives you accurate, working examples of every trigger type and condition structure the game uses, which you can then copy and adapt for your own advancements. To export just one advancement instead of all of them, pass its resource location:
Run /ca generate resource_locations first to dump every advancement ID to customadvancements/resource_locations.txt. That makes it easy to find the exact ID of an advancement you want to inspect or override before running the generate command.
See Commands for the full command reference, and Structure for the complete field reference used in these examples.