26.1.2 fluids

Fluids

Fluid with Contact Effects — Full Example

{
  "id": "poison_lake",
  "type": "fluid",
  "names": {
    "en_us": "Poison Lake",
    "es_mx": "Lago Venenoso"
  },
  "bucket_names": {
    "en_us": "{fluid_name} Bucket",
    "es_mx": "Cubeta de {fluid_name}"
  },
  "light_level": 3,
  "tick_rate": 10,
  "spread_distance": 6,
  "burns_entities": false,
  "contact_effect_interval": 2.0,
  "contact_effects": [
    { "effect": "minecraft:poison",   "amplifier": 0, "duration": 3 },
    { "effect": "minecraft:slowness", "amplifier": 1, "duration": 3 }
  ],
  "texture": {
    "refs": {
      "still": "minecraft:block/water_still",
      "flowing": "minecraft:block/water_flow"
    }
  }
}

Lava-like Fluid — Full Example

{
  "id": "magma_fluid",
  "type": "fluid",
  "names": {
    "en_us": "Magma Flow",
    "es_mx": "Flujo de Magma"
  },
  "bucket_names": {
    "en_us": "{fluid_name} Bucket",
    "es_mx": "Cubeta de {fluid_name}"
  },
  "light_level": 15,
  "tick_rate": 30,
  "spread_distance": 4,
  "burns_entities": true,
  "burn_duration": 8,
  "contact_effect_interval": 1.0,
  "contact_effects": [
    { "effect": "minecraft:weakness",       "amplifier": 1, "duration": 5 },
    { "effect": "minecraft:mining_fatigue", "amplifier": 0, "duration": 5 }
  ],
  "texture": {
    "refs": {
      "still": "minecraft:block/lava_still",
      "flowing": "minecraft:block/lava_flow"
    }
  }
}

Fluid textures take the short form — minecraft:block/lava_still, not the full path. A fluid sprite is stitched into the block atlas, and that is how the atlas addresses it.

Declaring neither still nor flowing makes the fluid a water reskin, which is also what gives it water's blue tint. Declaring one and not the other is rejected: the fluid would draw its own still texture and water's flowing one.

Animated fluids need their .mcmeta beside the PNG — see Textures & Models.

Fluid Fields

Field	Type	Default	Description
light_level	Int	0	Light emitted by the fluid block (0–15)
color	String	"0xFFFFFFFF"	Tint color in ARGB hex format, e.g. "0xFF3F76E4"
tick_rate	Int	5	Ticks between each spread step. Lower = faster. Water=5, Lava=30
spread_distance	Int	8	Max horizontal spread in blocks. Water=8, Lava=4
burns_entities	Boolean	false	Sets entities on fire like lava — affects players, mobs and dropped items (fire-immune mobs are unaffected)
burn_duration	Int	5	Seconds the entity burns. Only if burns_entities is true
contact_effect_interval	Float	1.0	Seconds between each effect application while in the fluid
contact_effects	List	—	Effects applied to living entities (players and mobs) while submerged
contact_effects[].effect	String	—	Effect ID, e.g. "minecraft:poison"
contact_effects[].amplifier	Int	0	Effect level minus 1
contact_effects[].duration	Int	3	Duration in seconds per application

contact_effects[].duration should be at least ~2 seconds longer than contact_effect_interval, or damage-over-time effects (poison, wither) won't get the chance to tick. The defaults (duration 3, interval 1.0) are safe.

⚠️ Dropped items inside a fluid with burns_entities: true catch fire and are destroyed, exactly like in lava — players who die in it will lose their drops. Design accordingly.