Layers

A layer is a choice a player makes. The base Origins mod ships one layer — origins:origin — and that’s the “pick your origin” screen everyone knows. Layers are what actually put origins in front of players; an origin not in any layer is invisible.

You can add origins to the existing layer, or define brand-new layers (a second, independent choice — say a “class” alongside an “origin”).

A layer file#

Layers live in data/<namespace>/origin_layers/.

{
  "order": 0,
  "enabled": true,
  "name": "layer.my_pack.origin.name",
  "origins": [
    "my_pack:merling",
    "my_pack:ember",
    "origins:human"
  ]
}

Core fields#

Field	Type	Default	Purpose
origins	list of conditioned origin	required	The origins offered in this layer.
order	integer	0	Order when several layers are chosen in turn. Lowest first.
enabled	boolean	true	Whether the layer is active.
name	string	layer.<ns>.<path>.name	Translation key for the layer’s title.
gui_title	object	{}	choose_origin and view_origin translation keys for the two screens.
missing_name	string	""	Translation key shown when the player has no origin in this layer.
missing_description	string	""	Translation key for that placeholder’s description.
default_origin	identifier	—	Fallback for players this layer offers no choice to.
auto_choose	boolean	false	Skip the screen when the layer offers exactly one choosable origin.
hidden	boolean	false	Hide the layer from the origin-viewing screen.
random	object	—	Random-roll settings — see Randomised layers.
randomiser	object	—	Re-roll-over-a-life settings — see Lifecycle & re-rolls.
replace	boolean	false	Discard lower-priority packs’ version of this layer instead of merging into it.

name, missing_name, missing_description and both gui_title entries are translation keys, not literal text. Put the display string in your pack’s language file. A raw string still “works” — an unknown key renders as itself — but it will not translate.

Conditioned origins#

An entry in origins is either a plain identifier, or an object that gates a group of origins behind an entity condition — any of them, including origins:origin itself. The two forms mix freely in one list.

{
   "order":2,
   "auto_choose":true,
   "hidden":true,
   "name":"layer.my_pack.evolved.name",
   "origins":[
      {
         "condition":{
            "type":"origins:origin",
            "layer":"origins:origin",
            "origin":"my_pack:ember"
         },
         "origins":[
            "my_pack:ember_evolved"
         ]
      },
      {
         "condition":{
            "type":"origins:origin",
            "layer":"origins:origin",
            "origin":"my_pack:ember",
            "inverted":true
         },
         "origins":[
            "my_pack:unevolved"
         ]
      }
   ]
}

The condition is re-evaluated every time the layer’s options are listed, so a layer can react to what the player picked in an earlier layer, to a resource value, or to anything else an entity condition can see.

The origins in a gated group must be choosable ("unchoosable": true excludes them). An unchoosable origin never appears as an option and auto_choose will not pick it.

auto_choose and default_origin#

These are how a conditioned layer grants an origin without ever showing a screen — the pattern above needs one of them, or the player is asked to “choose” from a list of one.

• auto_choose — when the layer offers exactly one choosable origin for that player, it is assigned silently and no screen opens. With two or more options the player still chooses normally.
• default_origin — the fallback for a layer the player is never asked about. It is applied only when the layer offers them nothing choosable and no random roll, on join and on data-pack reload. A layer that can be chosen always shows its screen — default_origin never pre-empts a real choice.

Both are re-checked on join, on data-pack reload, after every origin the player picks, and on Orb of Origin use — so a layer whose condition only becomes true after an earlier layer is chosen resolves in the same breath as that choice.

Adding to an existing layer#

To drop your origins into the vanilla Origins screen, define a layer with the same id — origins:origin — in your own pack listing just your origins. Origins merges layers that share an id across data packs, so your entries appear alongside the built-in ones rather than replacing them.

// data/origins/origin_layers/origin.json  (in your pack)
{
   "origins":[
      "my_pack:merling",
      "my_pack:ember"
   ]
}

Set "replace": true in the higher-priority pack to throw the merged result away and use only your file.

Randomised layers#

Layers can hand out a random origin instead of letting the player choose — the basis for “random origin” servers. Everything lives in the random object:

Field	Type	Default	Purpose
allow	boolean	true	Offer the “random” option in the screen.
allow_unchoosable	boolean	false	Let the roll land on unchoosable origins.
exclude	list of identifier	—	Origins the roll never picks.
style	string	"uniform"	uniform, weighted, or roll (alias gacha) for the rolling animation.
weights	map of identifier → integer	{}	Per-origin weighting, for style: weighted.
roll_duration	integer	80	Animation length in ticks, for style: roll.

{
   "origins":[
      "my_pack:merling",
      "my_pack:ember"
   ],
   "random":{
      "allow":true,
      "style":"weighted",
      "weights":{
         "my_pack:ember":3
      }
   }
}

The flat allow_random, allow_random_unchoosable and exclude_random fields are the pre-random-block spelling and still load. A random block wins over all three.

Lifecycle & re-rolls#

The randomiser object controls what happens over a life:

Field	Type	Default	Purpose
on_first_join	boolean	false	Roll an origin when the player first joins.
on_death	boolean	false	Re-roll on death.
on_sleep	boolean	false	Re-roll after sleeping.
deaths_between_randomises	integer	1	Deaths required before a re-roll.
sleeps_between_randomises	integer	1	Sleeps required before a re-roll.
lives	object	{}	enabled (boolean, false) and starting (integer, 10) — lives before the layer locks.
reset_to_default_on_death	boolean	false	Revert to default_origin on death instead of re-rolling.
show_screen_on_death	boolean	false	Open the choose screen on death rather than rolling.
allow_duplicate	boolean	false	Let a re-roll land on the origin the player already had.
broadcast_messages	boolean	true	Announce re-rolls in chat.

These options are how “hardcore origins”, “randomiser”, and “one life per origin” servers are configured — all in JSON, no code.