Blood Values

Vampirism assigns blood-related values to items, entities and fluids through three NeoForge data maps. Each is an ordinary data pack file, so any pack can add, override or remove entries.

All three data maps are synced to the client.

JSON Schemas

• Item blood – schemas/item_blood.schema.json
• Entity blood – schemas/entity_blood.schema.json
• Fluid blood conversion – schemas/fluid_blood_conversion.schema.json

Data map file format

Every data map file uses the standard NeoForge wrapper:

{
  "replace": false,
  "values": {
    "<id-or-#tag>": { /* entry */ }
  },
  "remove": [ "<id-or-#tag>" ]
}

Field	Type	Description
replace	bool	true clears all previously loaded entries first. Defaults to false (merge).
values	object	Maps a registry id (or a #tag) to an entry. Later data packs override earlier ones.
remove	array	Ids (or #tags) to drop from the merged map. Optional.

Entries also accept a neoforge:conditions array to load them only when another mod/item is present.

Item blood

data/<namespace>/data_maps/item/item_blood.json

Data map vampirism:item_blood. Sets how much impure blood (in mB) the Blood Grinder produces from one of the item. 0 marks the item as not grindable.

If an item has no entry, Vampirism falls back to nutrition × 10 for uncooked items in the #minecraft:meat tag, and 0 otherwise.

data/vampirism/data_maps/item/item_blood.json

{
  "values": {
    "minecraft:beef": { "blood": 200 },
    "minecraft:mutton": 100,
    "minecraft:cooked_beef": { "blood": 0 }
  }
}

Field	Type	Description
blood	int (>= 0)	mB of impure blood produced per item. 0 = not grindable.

The entry may be written as a bare integer ("minecraft:mutton": 100) instead of the object form.

Entity blood

data/<namespace>/data_maps/entity_type/entity_blood.json

Data map vampirism:entity_blood. Sets how much blood a creature holds when a vampire bites it, and gates whether the creature can be converted at all. 0 marks the entity as not biteable (and not convertible).

If an entity has no entry and the autoCalculateEntityBlood server config is enabled, Vampirism derives a value from the creature's hitbox size (capped at 15, and forced to 0 for creatures with more than 50 max health). A data map entry always wins over the auto-calculation.

data/vampirism/data_maps/entity_type/entity_blood.json

{
  "values": {
    "minecraft:cow": { "blood": 10 },
    "minecraft:cat": { "blood": 3 },
    "minecraft:chicken": { "blood": 0 }
  }
}

Field	Type	Description
blood	int (>= 0)	Blood units the creature holds. 0 = not biteable / not convertible.

The entry must be the object form ({ "blood": N }).

Fluid blood conversion

data/<namespace>/data_maps/fluid/fluid_blood_conversion.json

Data map vampirism:fluid_blood_conversion. Sets the conversion ratio a Blood Sieve applies when turning a fluid into Blood: output_blood = conversionRate × input_amount. 0 means the fluid cannot be converted.

Vampirism ships this map empty; vampirism:impure_blood conversion is handled in code. Use it to make third-party fluids convertible.

data/vampirism/data_maps/fluid/fluid_blood_conversion.json

{
  "values": {
    "examplemod:diluted_blood": { "conversionRate": 0.75 }
  }
}

Field	Type	Description
conversionRate	float	Fraction of the input fluid amount returned as blood. 0 = no conversion.

The entry may be written as a bare number ("examplemod:diluted_blood": 0.75) instead of the object form.