feat: add compute command

crates/pumpkin-command/src/argument_types/resource.rs

@@ -107,8 +107,35 @@ pub static MOB_EFFECT_ARGUMENT: ResourceArgument =
             .map(|value| value as &'static (dyn Any + Send + Sync))
     });
 
+pub type DynamicDamageTypeResolver =
+    Box<dyn Fn(&str) -> Option<&'static pumpkin_data::damage::DamageType> + Send + Sync>;
+
+pub static DYNAMIC_DAMAGE_TYPE_RESOLVER: std::sync::RwLock<Option<DynamicDamageTypeResolver>> =
+    std::sync::RwLock::new(None);
+pub static DYNAMIC_DAMAGE_TYPE_NAMES: std::sync::RwLock<Vec<String>> =
+    std::sync::RwLock::new(Vec::new());
+
+pub fn register_dynamic_damage_types(resolver: DynamicDamageTypeResolver, names: Vec<String>) {
+    if let Ok(mut guard) = DYNAMIC_DAMAGE_TYPE_RESOLVER.write() {
+        *guard = Some(resolver);
+    }
+    if let Ok(mut guard) = DYNAMIC_DAMAGE_TYPE_NAMES.write() {
+        *guard = names;
+    }
+}
+
 pub static DAMAGE_TYPE_ARGUMENT: ResourceArgument =
     ResourceArgument(DAMAGE_TYPE_REGISTRY, &|id: Identifier| {
+        if let Ok(guard) = DYNAMIC_DAMAGE_TYPE_RESOLVER.read()
+            && let Some(resolver) = guard.as_ref()
+        {
+            let id_str = id.to_string();
+            let path_str = id.path();
+            if let Some(dt) = resolver(&id_str).or_else(|| resolver(path_str)) {
+                return Some(dt as &'static (dyn Any + Send + Sync));
+            }
+        }
+
         let dt = pumpkin_data::damage::DamageType::from_name(id.path())
             .or_else(|| pumpkin_data::damage::DamageType::from_name(&id.to_string()))?;
         let idx = dt.id as usize;
@@ -207,7 +234,13 @@ impl<S: crate::source::CommandSource> ArgumentType<S> for ResourceArgument {
             let types = DAMAGE_TYPES
                 .iter()
                 .map(|dt| format!("minecraft:{}", dt.message_id));
-            suggestions_builder.filter_and_suggest_iter(types).build()
+            let extra = DYNAMIC_DAMAGE_TYPE_NAMES
+                .read()
+                .map(|g| g.clone())
+                .unwrap_or_default();
+            suggestions_builder
+                .filter_and_suggest_iter(types.chain(extra))
+                .build()
         } else {
             Suggestions::empty()
         }

crates/pumpkin-util/src/loot_table.rs

@@ -75,3 +75,144 @@ pub struct LootTable {
 pub type ChestLootEntry = LootEntry;
 pub type ChestLootPool = LootPool;
 pub type ChestLootTable = LootTable;
+
+/// Conditions required for an entry or pool to be eligible for dynamic loot generation.
+#[derive(Clone, Debug, PartialEq, Default)]
+pub enum DynamicLootCondition {
+    #[default]
+    None,
+    SilkTouch,
+    NoSilkTouch,
+    Shears,
+    SilkTouchOrShears,
+    NoSilkTouchOrShears,
+    SurvivesExplosion,
+    KilledByPlayer,
+    RandomChance {
+        chance: f32,
+    },
+    RandomChanceWithEnchantedBonus {
+        unenchanted_chance: f32,
+        enchanted_chance_base: f32,
+        enchanted_chance_per_level_above_first: f32,
+    },
+    TableBonus {
+        chances: Box<[f32]>,
+    },
+    AllOf(Vec<Self>),
+    AnyOf(Vec<Self>),
+    Inverted(Box<Self>),
+    EntityOnFire,
+    WeatherCheck {
+        raining: Option<bool>,
+        thundering: Option<bool>,
+    },
+}
+
+impl From<LootCondition> for DynamicLootCondition {
+    fn from(cond: LootCondition) -> Self {
+        match cond {
+            LootCondition::None => Self::None,
+            LootCondition::SilkTouch => Self::SilkTouch,
+            LootCondition::NoSilkTouch => Self::NoSilkTouch,
+            LootCondition::Shears => Self::Shears,
+            LootCondition::SilkTouchOrShears => Self::SilkTouchOrShears,
+            LootCondition::NoSilkTouchOrShears => Self::NoSilkTouchOrShears,
+            LootCondition::SurvivesExplosion => Self::SurvivesExplosion,
+            LootCondition::KilledByPlayer => Self::KilledByPlayer,
+            LootCondition::RandomChance { chance } => Self::RandomChance { chance },
+            LootCondition::RandomChanceWithEnchantedBonus {
+                unenchanted_chance,
+                enchanted_chance_base,
+                enchanted_chance_per_level_above_first,
+            } => Self::RandomChanceWithEnchantedBonus {
+                unenchanted_chance,
+                enchanted_chance_base,
+                enchanted_chance_per_level_above_first,
+            },
+            LootCondition::TableBonus { chances } => Self::TableBonus {
+                chances: chances.to_vec().into_boxed_slice(),
+            },
+            LootCondition::AllOf(conditions) => {
+                Self::AllOf(conditions.iter().copied().map(Self::from).collect())
+            }
+        }
+    }
+}
+
+/// A single item entry inside a dynamic loot pool.
+#[derive(Clone, Debug)]
+pub struct DynamicLootEntry {
+    /// Registry name of the item (e.g. `"minecraft:diamond"`).
+    pub item: String,
+    /// Relative probability weight; higher values are more likely.
+    pub weight: i32,
+    /// Minimum stack size (inclusive).
+    pub min_count: i32,
+    /// Maximum stack size (inclusive).
+    pub max_count: i32,
+    /// Condition required for this entry to be eligible.
+    pub condition: DynamicLootCondition,
+    /// Bonus formula to apply with fortune / looting (if any).
+    pub bonus_formula: Option<LootBonusFormula>,
+}
+
+impl From<LootEntry> for DynamicLootEntry {
+    fn from(e: LootEntry) -> Self {
+        Self {
+            item: e.item.to_string(),
+            weight: e.weight,
+            min_count: e.min_count,
+            max_count: e.max_count,
+            condition: DynamicLootCondition::from(e.condition),
+            bonus_formula: e.bonus_formula,
+        }
+    }
+}
+
+/// One roll pool inside a dynamic loot table.
+#[derive(Clone, Debug)]
+pub struct DynamicLootPool {
+    /// Item entries eligible for selection each roll.
+    pub entries: Vec<DynamicLootEntry>,
+    /// Minimum number of roll attempts (inclusive).
+    pub min_rolls: i32,
+    /// Maximum number of roll attempts (inclusive).
+    pub max_rolls: i32,
+    /// Weight of the implicit "empty" (no item) outcome per roll.
+    pub empty_weight: i32,
+    /// Condition required for this entire pool to run.
+    pub condition: DynamicLootCondition,
+}
+
+impl From<LootPool> for DynamicLootPool {
+    fn from(p: LootPool) -> Self {
+        Self {
+            entries: p
+                .entries
+                .iter()
+                .copied()
+                .map(DynamicLootEntry::from)
+                .collect(),
+            min_rolls: p.min_rolls,
+            max_rolls: p.max_rolls,
+            empty_weight: p.empty_weight,
+            condition: DynamicLootCondition::from(p.condition),
+        }
+    }
+}
+
+/// A complete dynamic loot table consisting of one or more pools.
+#[derive(Clone, Debug, Default)]
+pub struct DynamicLootTable {
+    /// All pools to roll when generating loot for this table.
+    pub pools: Vec<DynamicLootPool>,
+}
+
+impl From<&LootTable> for DynamicLootTable {
+    fn from(t: &LootTable) -> Self {
+        Self {
+            pools: t.pools.iter().copied().map(DynamicLootPool::from).collect(),
+        }
+    }
+}

crates/pumpkin/src/block/entities/trial_spawner.rs

@@ -1055,11 +1055,11 @@ impl TrialSpawner {
         }
 
         if let Some(equip) = equipment_loot_table
-            && let Some(loot_table) = pumpkin_data::loot_table::get_loot_table(&equip)
+            && let Some(loot_table) = world.get_loot_table(&equip)
             && let Some(living) = entity.get_living_entity()
         {
             let seed = rand::random::<i64>();
-            let items = crate::world::loot::generate_loot(loot_table, seed);
+            let items = loot_table.generate_loot(seed);
             let mut equipment = living
                 .entity_equipment
                 .lock()
@@ -1126,10 +1126,10 @@ impl TrialSpawner {
     ) {
         let mut dropped_any = false;
         if let Some(key) = ejecting_loot_table
-            && let Some(loot_table) = pumpkin_data::loot_table::get_loot_table(key)
+            && let Some(loot_table) = world.get_loot_table(key)
         {
             let seed = rand::random::<i64>();
-            let items = crate::world::loot::generate_loot(loot_table, seed);
+            let items = loot_table.generate_loot(seed);
             for stack in items {
                 world.drop_stack(&spawner_pos, stack);
                 dropped_any = true;

crates/pumpkin/src/block/mod.rs

@@ -460,9 +460,9 @@ pub fn drop_loot(
     params: &LootContextParameters,
 ) {
     let key = format!("minecraft:blocks/{}", block.name);
-    if let Some(loot_table) = pumpkin_data::loot_table::get_loot_table(&key) {
+    if let Some(loot_table) = world.get_loot_table(&key) {
         let seed: i64 = rand::random();
-        let items = crate::world::loot::generate_loot_with_context(loot_table, seed, params);
+        let items = crate::world::loot::generate_loot_from_handle(&loot_table, seed, params);
         if !items.is_empty() {
             let mut event = crate::plugin::block::block_drop_item::BlockDropItemEvent {
                 block_pos: *pos,

crates/pumpkin/src/command/commands/loot.rs

@@ -27,6 +27,8 @@ use crate::command::errors::command_syntax_error::CommandSyntaxError;
 use crate::command::errors::error_types::CommandErrorType;
 use crate::command::node::dispatcher::CommandDispatcher;
 use crate::command::node::{CommandExecutor, CommandExecutorResult};
+use crate::command::suggestion::provider::{SuggestionProvider, SuggestionProviderResult};
+use crate::command::suggestion::suggestions::SuggestionsBuilder;
 use crate::entity::EntityBase;
 use crate::world::loot::LootContextParameters;
 
@@ -39,6 +41,23 @@ static ERROR_INVALID_LOOT_TABLE: CommandErrorType<1> = CommandErrorType::new(
     "Loot table '%s' not found",
 );
 
+struct LootTableSuggestionProvider;
+
+impl SuggestionProvider for LootTableSuggestionProvider {
+    fn suggest(
+        &self,
+        context: &CommandContext,
+        mut builder: SuggestionsBuilder,
+    ) -> SuggestionProviderResult {
+        let server = context.server();
+        let custom_names = server.datapack_manager.get_loot_table_names();
+        for name in custom_names {
+            builder = builder.suggest(name);
+        }
+        builder.build()
+    }
+}
+
 static ERROR_NO_HELD_ITEMS: CommandErrorType<1> = CommandErrorType::new(
     translation::java::COMMANDS_DROP_NO_HELD_ITEMS,
     translation::java::COMMANDS_DROP_NO_HELD_ITEMS,
@@ -345,8 +364,11 @@ impl CommandExecutor for LootExecutor {
                     ToolSource::OffHand => get_hand_item(context, false)?,
                 };
 
-                let loot_table =
-                    pumpkin_data::loot_table::get_loot_table(&key).ok_or_else(|| {
+                let loot_table = context
+                    .server()
+                    .datapack_manager
+                    .get_loot_table(&key)
+                    .ok_or_else(|| {
                         ERROR_INVALID_LOOT_TABLE
                             .create_without_context(TextComponent::text(loot_table_str.to_string()))
                     })?;
@@ -361,7 +383,7 @@ impl CommandExecutor for LootExecutor {
                     ..Default::default()
                 };
                 let seed: i64 = rand::random();
-                drops = crate::world::loot::generate_loot_with_context(loot_table, seed, &params);
+                drops = crate::world::loot::generate_loot_from_handle(&loot_table, seed, &params);
             }
             Source::Loot => {
                 let loot_table_str = StringArgumentType::get(context, "loot_table")?;
@@ -371,8 +393,11 @@ impl CommandExecutor for LootExecutor {
                     format!("minecraft:{loot_table_str}")
                 };
 
-                let loot_table =
-                    pumpkin_data::loot_table::get_loot_table(&key).ok_or_else(|| {
+                let loot_table = context
+                    .server()
+                    .datapack_manager
+                    .get_loot_table(&key)
+                    .ok_or_else(|| {
                         ERROR_INVALID_LOOT_TABLE
                             .create_without_context(TextComponent::text(loot_table_str.to_string()))
                     })?;
@@ -382,7 +407,7 @@ impl CommandExecutor for LootExecutor {
                     ..Default::default()
                 };
                 let seed: i64 = rand::random();
-                drops = crate::world::loot::generate_loot_with_context(loot_table, seed, &params);
+                drops = crate::world::loot::generate_loot_from_handle(&loot_table, seed, &params);
             }
             Source::Kill => {
                 let target_entities = EntityArgumentType::get_entities(context, "target_entity")?;
@@ -402,10 +427,13 @@ impl CommandExecutor for LootExecutor {
                 for entity in &target_entities {
                     let resource_name = entity.get_entity().entity_type.resource_name;
                     let key = format!("minecraft:entities/{resource_name}");
-                    if let Some(loot_table) = pumpkin_data::loot_table::get_loot_table(&key) {
+                    if let Some(loot_table) = context.server().datapack_manager.get_loot_table(&key)
+                    {
                         let seed: i64 = rand::random();
-                        drops.extend(crate::world::loot::generate_loot_with_context(
-                            loot_table, seed, &params,
+                        drops.extend(crate::world::loot::generate_loot_from_handle(
+                            &loot_table,
+                            seed,
+                            &params,
                         ));
                         last_key = Some(key);
                     }
@@ -427,8 +455,11 @@ impl CommandExecutor for LootExecutor {
                 let block = world.get_block(&pos);
                 let key = format!("minecraft:blocks/{}", block.name);
 
-                let loot_table =
-                    pumpkin_data::loot_table::get_loot_table(&key).ok_or_else(|| {
+                let loot_table = context
+                    .server()
+                    .datapack_manager
+                    .get_loot_table(&key)
+                    .ok_or_else(|| {
                         ERROR_NO_BLOCK_LOOT_TABLE
                             .create_without_context(TextComponent::text(block.name.to_string()))
                     })?;
@@ -451,7 +482,7 @@ impl CommandExecutor for LootExecutor {
                     ..Default::default()
                 };
                 let seed: i64 = rand::random();
-                drops = crate::world::loot::generate_loot_with_context(loot_table, seed, &params);
+                drops = crate::world::loot::generate_loot_from_handle(&loot_table, seed, &params);
                 table_id_for_callback = Some(key);
             }
         }
@@ -589,7 +620,9 @@ impl CommandExecutor for LootExecutor {
 fn add_sources(target: Target) -> Vec<LiteralArgumentBuilder> {
     vec![
         literal("fish").then(
-            argument("loot_table", StringArgumentType::SingleWord).then(
+            argument("loot_table", StringArgumentType::SingleWord)
+                .suggests(LootTableSuggestionProvider)
+                .then(
                     argument("fish_pos", BlockPosArgumentType)
                         .executes(LootExecutor {
                             target,
@@ -620,7 +653,9 @@ fn add_sources(target: Target) -> Vec<LiteralArgumentBuilder> {
                 ),
         ),
         literal("loot").then(
-            argument("loot_table", StringArgumentType::SingleWord).executes(LootExecutor {
+            argument("loot_table", StringArgumentType::SingleWord)
+                .suggests(LootTableSuggestionProvider)
+                .executes(LootExecutor {
                     target,
                     source: Source::Loot,
                 }),

crates/pumpkin/src/command/commands/mod.rs

@@ -14,6 +14,7 @@ mod banlist;
 mod bossbar;
 mod clear;
 mod clone;
+mod compute;
 mod damage;
 mod data;
 mod datapack;
@@ -174,6 +175,7 @@ pub fn default_dispatcher(
     effect::register(&mut dispatcher, registry);
     summon::register(&mut dispatcher, registry);
     swing::register(&mut dispatcher, registry);
+    compute::register(&mut dispatcher, registry);
     damage::register(&mut dispatcher, registry);
     rotate::register(&mut dispatcher, registry);
     tellraw::register(&mut dispatcher, registry);

crates/pumpkin/src/data/datapack/context_provider_loader.rs

@@ -0,0 +1,136 @@
+use std::collections::HashMap;
+use std::fs;
+use std::path::Path;
+
+use pumpkin_nbt::compound::NbtCompound;
+use pumpkin_nbt::tag::NbtTag;
+use serde_json::Value;
+use tracing::warn;
+
+pub type ContextProviderRegistry = HashMap<String, NbtTag>;
+
+#[must_use]
+pub fn json_value_to_nbt(value: &Value) -> NbtTag {
+    match value {
+        Value::Null => NbtTag::String(String::new().into()),
+        Value::Bool(val) => NbtTag::Byte(i8::from(*val)),
+        Value::Number(val) => val.as_i64().map_or_else(
+            || {
+                val.as_u64().map_or_else(
+                    || NbtTag::Double(val.as_f64().unwrap_or_default()),
+                    |u_val| {
+                        i32::try_from(u_val).map_or_else(
+                            |_| {
+                                #[allow(clippy::cast_precision_loss)]
+                                i64::try_from(u_val)
+                                    .map_or_else(|_| NbtTag::Double(u_val as f64), NbtTag::Long)
+                            },
+                            NbtTag::Int,
+                        )
+                    },
+                )
+            },
+            |i_val| i32::try_from(i_val).map_or(NbtTag::Long(i_val), NbtTag::Int),
+        ),
+        Value::String(val) => NbtTag::String(val.clone().into()),
+        Value::Array(values) => NbtTag::List(values.iter().map(json_value_to_nbt).collect()),
+        Value::Object(values) => {
+            let mut compound = NbtCompound::new();
+            for (name, val) in values {
+                compound.put(name, json_value_to_nbt(val));
+            }
+            NbtTag::Compound(compound)
+        }
+    }
+}
+
+pub fn load_context_providers_from_dir(
+    namespace: &str,
+    provider_dir: &Path,
+    registry: &mut ContextProviderRegistry,
+) -> usize {
+    if !provider_dir.is_dir() {
+        return 0;
+    }
+
+    let before = registry.len();
+    load_context_providers_recursive(namespace, provider_dir, provider_dir, registry);
+    registry.len() - before
+}
+
+fn load_context_providers_recursive(
+    namespace: &str,
+    base_dir: &Path,
+    current_dir: &Path,
+    registry: &mut ContextProviderRegistry,
+) {
+    let Ok(entries) = fs::read_dir(current_dir) else {
+        return;
+    };
+
+    for entry in entries.flatten() {
+        let path = entry.path();
+
+        if path.is_dir() {
+            load_context_providers_recursive(namespace, base_dir, &path, registry);
+        } else if path
+            .extension()
+            .is_some_and(|ext| ext.eq_ignore_ascii_case("json"))
+            && let Ok(rel_path) = path.strip_prefix(base_dir)
+        {
+            let mut stem_path = rel_path.to_string_lossy().to_string();
+
+            if let Some(stem) = stem_path.strip_suffix(".json") {
+                stem_path = stem.to_string();
+            }
+
+            let stem_path = stem_path.replace('\\', "/");
+            let provider_id = format!("{namespace}:{stem_path}");
+
+            match fs::read_to_string(&path) {
+                Ok(content) => match serde_json::from_str::<Value>(&content) {
+                    Ok(val) => {
+                        let tag = json_value_to_nbt(&val);
+                        registry.insert(provider_id, tag);
+                    }
+                    Err(e) => {
+                        warn!(
+                            "Failed to parse context provider '{provider_id}' from '{}': {e}",
+                            path.display()
+                        );
+                    }
+                },
+                Err(e) => {
+                    warn!(
+                        "Failed to read context provider file '{}': {e}",
+                        path.display()
+                    );
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn json_value_to_nbt_works() {
+        let json: Value = serde_json::json!({
+            "type": "minecraft:add",
+            "left": 10,
+            "right": 20.5,
+            "items": ["a", "b"]
+        });
+
+        let tag = json_value_to_nbt(&json);
+        if let NbtTag::Compound(compound) = tag {
+            assert_eq!(compound.get_string("type"), Some("minecraft:add"));
+            assert_eq!(compound.get_int("left"), Some(10));
+            assert_eq!(compound.get_double("right"), Some(20.5));
+        } else {
+            panic!("Expected compound");
+        }
+    }
+}

crates/pumpkin/src/data/datapack/damage_type_loader.rs

@@ -0,0 +1,417 @@
+use std::collections::HashMap;
+use std::fs;
+use std::path::Path;
+
+use pumpkin_data::damage::{DamageEffects, DamageScaling, DamageType, DeathMessageType};
+use pumpkin_data::registry::RegistryEntryData;
+use pumpkin_nbt::{Nbt, NbtCompound};
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum DamageScalingWrapper {
+    Never,
+    WhenCausedByLivingNonPlayer,
+    Always,
+}
+
+impl From<DamageScalingWrapper> for DamageScaling {
+    fn from(wrapper: DamageScalingWrapper) -> Self {
+        match wrapper {
+            DamageScalingWrapper::Never => Self::Never,
+            DamageScalingWrapper::WhenCausedByLivingNonPlayer => Self::WhenCausedByLivingNonPlayer,
+            DamageScalingWrapper::Always => Self::Always,
+        }
+    }
+}
+
+impl DamageScalingWrapper {
+    #[must_use]
+    pub const fn as_str(&self) -> &'static str {
+        match self {
+            Self::Never => "never",
+            Self::WhenCausedByLivingNonPlayer => "when_caused_by_living_non_player",
+            Self::Always => "always",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum DamageEffectsWrapper {
+    Hurt,
+    Thorns,
+    Drowning,
+    Burning,
+    Poking,
+    Freezing,
+}
+
+impl From<DamageEffectsWrapper> for DamageEffects {
+    fn from(wrapper: DamageEffectsWrapper) -> Self {
+        match wrapper {
+            DamageEffectsWrapper::Hurt => Self::Hurt,
+            DamageEffectsWrapper::Thorns => Self::Thorns,
+            DamageEffectsWrapper::Drowning => Self::Drowning,
+            DamageEffectsWrapper::Burning => Self::Burning,
+            DamageEffectsWrapper::Poking => Self::Poking,
+            DamageEffectsWrapper::Freezing => Self::Freezing,
+        }
+    }
+}
+
+impl DamageEffectsWrapper {
+    #[must_use]
+    pub const fn as_str(&self) -> &'static str {
+        match self {
+            Self::Hurt => "hurt",
+            Self::Thorns => "thorns",
+            Self::Drowning => "drowning",
+            Self::Burning => "burning",
+            Self::Poking => "poking",
+            Self::Freezing => "freezing",
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "snake_case")]
+pub enum DeathMessageTypeWrapper {
+    Default,
+    FallVariants,
+    IntentionalGameDesign,
+}
+
+impl From<DeathMessageTypeWrapper> for DeathMessageType {
+    fn from(wrapper: DeathMessageTypeWrapper) -> Self {
+        match wrapper {
+            DeathMessageTypeWrapper::Default => Self::Default,
+            DeathMessageTypeWrapper::FallVariants => Self::FallVariants,
+            DeathMessageTypeWrapper::IntentionalGameDesign => Self::IntentionalGameDesign,
+        }
+    }
+}
+
+impl DeathMessageTypeWrapper {
+    #[must_use]
+    pub const fn as_str(&self) -> &'static str {
+        match self {
+            Self::Default => "default",
+            Self::FallVariants => "fall_variants",
+            Self::IntentionalGameDesign => "intentional_game_design",
+        }
+    }
+}
+
+/// A parsed damage type definition from a datapack JSON file.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct DamageTypeDefinition {
+    pub message_id: String,
+    pub scaling: DamageScalingWrapper,
+    #[serde(default)]
+    pub exhaustion: f32,
+    #[serde(default)]
+    pub effects: Option<DamageEffectsWrapper>,
+    #[serde(default)]
+    pub death_message_type: Option<DeathMessageTypeWrapper>,
+}
+
+/// A registered damage type in the runtime registry.
+#[derive(Clone, Debug)]
+pub struct DamageTypeEntry {
+    pub id: String,
+    pub numeric_id: u8,
+    pub definition: DamageTypeDefinition,
+    pub damage_type: DamageType,
+    pub nbt_data: Box<[u8]>,
+}
+
+impl DamageTypeEntry {
+    #[must_use]
+    pub fn to_registry_entry(&self) -> RegistryEntryData {
+        RegistryEntryData {
+            entry_id: self.id.clone(),
+            data: Some(self.nbt_data.clone()),
+        }
+    }
+}
+
+pub type DamageTypeRegistry = HashMap<String, DamageTypeEntry>;
+
+/// Encodes a `DamageTypeDefinition` into a `pumpkin_data::damage::DamageType`.
+#[must_use]
+pub fn to_damage_type(numeric_id: u8, def: &DamageTypeDefinition) -> DamageType {
+    DamageType {
+        death_message_type: def
+            .death_message_type
+            .map_or(DeathMessageType::Default, Into::into),
+        exhaustion: def.exhaustion,
+        effects: def.effects.map(Into::into),
+        message_id: Box::leak(def.message_id.clone().into_boxed_str()),
+        scaling: def.scaling.into(),
+        id: numeric_id,
+    }
+}
+
+/// Encodes the damage type definition into binary NBT payload.
+#[must_use]
+pub fn to_registry_nbt_bytes(def: &DamageTypeDefinition) -> Box<[u8]> {
+    let mut nbt = NbtCompound::new();
+    nbt.put_string("message_id", def.message_id.clone());
+    nbt.put_string("scaling", def.scaling.as_str().to_string());
+    nbt.put_double("exhaustion", f64::from(def.exhaustion));
+
+    if let Some(effects) = def.effects {
+        nbt.put_string("effects", effects.as_str().to_string());
+    }
+
+    if let Some(dmt) = def.death_message_type
+        && dmt != DeathMessageTypeWrapper::Default
+    {
+        nbt.put_string("death_message_type", dmt.as_str().to_string());
+    }
+
+    Nbt::from(nbt).write_unnamed().to_vec().into_boxed_slice()
+}
+
+/// Encodes the damage type definition into a `RegistryEntryData` with binary NBT payload.
+#[must_use]
+pub fn to_registry_entry(entry_id: String, def: &DamageTypeDefinition) -> RegistryEntryData {
+    RegistryEntryData {
+        entry_id,
+        data: Some(to_registry_nbt_bytes(def)),
+    }
+}
+
+/// Loads all damage type JSON definitions from a directory into the definition registry.
+pub fn load_damage_types_from_dir<S: std::hash::BuildHasher>(
+    namespace: &str,
+    dir: &Path,
+    registry: &mut HashMap<String, DamageTypeDefinition, S>,
+) -> usize {
+    if !dir.is_dir() {
+        return 0;
+    }
+    let before = registry.len();
+    load_damage_types_recursive(namespace, dir, dir, registry);
+    registry.len() - before
+}
+
+fn load_damage_types_recursive<S: std::hash::BuildHasher>(
+    namespace: &str,
+    base_dir: &Path,
+    current_dir: &Path,
+    registry: &mut HashMap<String, DamageTypeDefinition, S>,
+) {
+    let Ok(entries) = fs::read_dir(current_dir) else {
+        return;
+    };
+    for entry in entries.flatten() {
+        let path = entry.path();
+        if path.is_dir() {
+            load_damage_types_recursive(namespace, base_dir, &path, registry);
+        } else if path
+            .extension()
+            .is_some_and(|ext| ext.eq_ignore_ascii_case("json"))
+            && let Ok(rel_path) = path.strip_prefix(base_dir)
+        {
+            let mut stem_path = rel_path.to_string_lossy().to_string();
+            if let Some(stem) = stem_path.strip_suffix(".json") {
+                stem_path = stem.to_string();
+            }
+            let stem_path = stem_path.replace('\\', "/");
+            let damage_type_id = format!("{namespace}:{stem_path}");
+
+            if let Ok(content) = fs::read_to_string(&path)
+                && let Ok(definition) = serde_json::from_str::<DamageTypeDefinition>(&content)
+            {
+                registry.insert(damage_type_id, definition);
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_full_damage_type_json() {
+        let json = r#"{
+            "message_id": "bleed",
+            "scaling": "when_caused_by_living_non_player",
+            "exhaustion": 0.25,
+            "effects": "burning",
+            "death_message_type": "intentional_game_design"
+        }"#;
+
+        let def: DamageTypeDefinition = serde_json::from_str(json).unwrap();
+        assert_eq!(def.message_id, "bleed");
+        assert_eq!(
+            def.scaling,
+            DamageScalingWrapper::WhenCausedByLivingNonPlayer
+        );
+        assert!((def.exhaustion - 0.25).abs() < 1e-6);
+        assert_eq!(def.effects, Some(DamageEffectsWrapper::Burning));
+        assert_eq!(
+            def.death_message_type,
+            Some(DeathMessageTypeWrapper::IntentionalGameDesign)
+        );
+
+        let dt = to_damage_type(52, &def);
+        assert_eq!(dt.id, 52);
+        assert_eq!(dt.message_id, "bleed");
+        assert_eq!(dt.scaling, DamageScaling::WhenCausedByLivingNonPlayer);
+        assert_eq!(dt.effects, Some(DamageEffects::Burning));
+        assert_eq!(
+            dt.death_message_type,
+            DeathMessageType::IntentionalGameDesign
+        );
+    }
+
+    #[test]
+    fn parse_minimal_damage_type_json() {
+        let json = r#"{
+            "message_id": "simple",
+            "scaling": "never"
+        }"#;
+
+        let def: DamageTypeDefinition = serde_json::from_str(json).unwrap();
+        assert_eq!(def.message_id, "simple");
+        assert_eq!(def.scaling, DamageScalingWrapper::Never);
+        assert_eq!(def.exhaustion, 0.0);
+        assert_eq!(def.effects, None);
+        assert_eq!(def.death_message_type, None);
+
+        let dt = to_damage_type(51, &def);
+        assert_eq!(dt.id, 51);
+        assert_eq!(dt.message_id, "simple");
+        assert_eq!(dt.scaling, DamageScaling::Never);
+        assert_eq!(dt.effects, None);
+        assert_eq!(dt.death_message_type, DeathMessageType::Default);
+    }
+
+    #[test]
+    fn to_registry_entry_encodes_valid_nbt() {
+        let def = DamageTypeDefinition {
+            message_id: "frost".to_string(),
+            scaling: DamageScalingWrapper::Always,
+            exhaustion: 0.1,
+            effects: Some(DamageEffectsWrapper::Freezing),
+            death_message_type: Some(DeathMessageTypeWrapper::FallVariants),
+        };
+
+        let entry = to_registry_entry("custom:frost".to_string(), &def);
+        assert_eq!(entry.entry_id, "custom:frost");
+        assert!(entry.data.is_some());
+
+        let data = entry.data.unwrap();
+        let mut cursor = std::io::Cursor::new(&data[..]);
+        let mut reader = pumpkin_nbt::deserializer::NbtReadHelperJava::new(
+            pumpkin_nbt::deserializer::NbtStreamReader(&mut cursor),
+        );
+        let nbt = Nbt::read_unnamed(&mut reader).unwrap().root_tag;
+        assert_eq!(nbt.get_string("message_id"), Some("frost"));
+        assert_eq!(nbt.get_string("scaling"), Some("always"));
+        assert_eq!(nbt.get_string("effects"), Some("freezing"));
+        assert_eq!(nbt.get_string("death_message_type"), Some("fall_variants"));
+    }
+
+    #[test]
+    fn load_damage_types_from_directory_recursively() {
+        let temp_dir =
+            std::env::temp_dir().join(format!("pumpkin_test_dt_{}", uuid::Uuid::new_v4()));
+        let sub_dir = temp_dir.join("sub");
+        fs::create_dir_all(&sub_dir).unwrap();
+
+        let dt1_json = r#"{
+            "message_id": "bleeding",
+            "scaling": "never",
+            "exhaustion": 0.5
+        }"#;
+        fs::write(temp_dir.join("bleed.json"), dt1_json).unwrap();
+
+        let dt2_json = r#"{
+            "message_id": "radiation",
+            "scaling": "always",
+            "exhaustion": 1.0,
+            "effects": "poking"
+        }"#;
+        fs::write(sub_dir.join("rad.json"), dt2_json).unwrap();
+
+        let mut registry = HashMap::new();
+        let count = load_damage_types_from_dir("custom", &temp_dir, &mut registry);
+        assert_eq!(count, 2);
+        assert!(registry.contains_key("custom:bleed"));
+        assert!(registry.contains_key("custom:sub/rad"));
+
+        let rad_def = &registry["custom:sub/rad"];
+        assert_eq!(rad_def.message_id, "radiation");
+        assert_eq!(rad_def.scaling, DamageScalingWrapper::Always);
+        assert_eq!(rad_def.effects, Some(DamageEffectsWrapper::Poking));
+
+        let _ = fs::remove_dir_all(temp_dir);
+    }
+
+    #[test]
+    fn merge_damage_type_entries_preserves_vanilla_and_appends_custom() {
+        use crate::data::datapack::merge_damage_type_entries;
+
+        let vanilla = vec![
+            RegistryEntryData {
+                entry_id: "arrow".to_string(),
+                data: Some(vec![1, 2, 3].into_boxed_slice()),
+            },
+            RegistryEntryData {
+                entry_id: "cactus".to_string(),
+                data: Some(vec![4, 5, 6].into_boxed_slice()),
+            },
+        ];
+
+        let mut custom = HashMap::new();
+        let bleed_def = DamageTypeDefinition {
+            message_id: "bleed".to_string(),
+            scaling: DamageScalingWrapper::Never,
+            exhaustion: 0.1,
+            effects: None,
+            death_message_type: None,
+        };
+        let bleed_entry = DamageTypeEntry {
+            id: "custom:bleed".to_string(),
+            numeric_id: 51,
+            definition: bleed_def.clone(),
+            damage_type: to_damage_type(51, &bleed_def),
+            nbt_data: vec![7, 8, 9].into_boxed_slice(),
+        };
+        custom.insert("custom:bleed".to_string(), bleed_entry);
+
+        // Overriding vanilla "arrow"
+        let arrow_def = DamageTypeDefinition {
+            message_id: "custom_arrow".to_string(),
+            scaling: DamageScalingWrapper::Always,
+            exhaustion: 0.5,
+            effects: None,
+            death_message_type: None,
+        };
+        let arrow_override = DamageTypeEntry {
+            id: "minecraft:arrow".to_string(),
+            numeric_id: 0,
+            definition: arrow_def.clone(),
+            damage_type: to_damage_type(0, &arrow_def),
+            nbt_data: vec![99, 99].into_boxed_slice(),
+        };
+        custom.insert("minecraft:arrow".to_string(), arrow_override);
+
+        let merged = merge_damage_type_entries(&vanilla, &custom);
+        assert_eq!(merged.len(), 3);
+        // Arrow replaced in place at index 0
+        assert_eq!(merged[0].entry_id, "arrow");
+        assert_eq!(merged[0].data.as_deref(), Some(&[99, 99][..]));
+        // Cactus preserved at index 1
+        assert_eq!(merged[1].entry_id, "cactus");
+        assert_eq!(merged[1].data.as_deref(), Some(&[4, 5, 6][..]));
+        // Custom bleed appended at index 2
+        assert_eq!(merged[2].entry_id, "custom:bleed");
+        assert_eq!(merged[2].data.as_deref(), Some(&[7, 8, 9][..]));
+    }
+}

crates/pumpkin/src/data/datapack/loot_table_loader.rs

@@ -0,0 +1,503 @@
+use std::collections::HashMap;
+use std::fs;
+use std::path::Path;
+use std::sync::Arc;
+
+use pumpkin_util::loot_table::{
+    DynamicLootCondition, DynamicLootEntry, DynamicLootPool, DynamicLootTable, LootBonusFormula,
+};
+use serde_json::Value;
+
+/// Parses an entire loot table JSON string into a [`DynamicLootTable`].
+#[must_use]
+pub fn parse_loot_table(json_content: &str) -> Option<DynamicLootTable> {
+    let root: Value = serde_json::from_str(json_content).ok()?;
+    let pools_val = root.get("pools").and_then(Value::as_array)?;
+
+    let pools = pools_val.iter().map(parse_pool).collect();
+
+    Some(DynamicLootTable { pools })
+}
+
+fn parse_pool(val: &Value) -> DynamicLootPool {
+    let (min_rolls, max_rolls) = val.get("rolls").map_or((1, 1), parse_rolls);
+
+    let mut entries = Vec::new();
+    let mut empty_weight = 0;
+
+    if let Some(entries_val) = val.get("entries").and_then(Value::as_array) {
+        for entry_val in entries_val {
+            parse_entry(entry_val, &mut entries, &mut empty_weight);
+        }
+    }
+
+    let pool_conditions = val.get("conditions").map_or(Vec::new(), parse_conditions);
+    let condition = combine_conditions(pool_conditions);
+
+    DynamicLootPool {
+        entries,
+        min_rolls,
+        max_rolls,
+        empty_weight,
+        condition,
+    }
+}
+
+fn parse_rolls(val: &Value) -> (i32, i32) {
+    if let Some(n) = val.as_i64() {
+        let r = n as i32;
+        return (r, r);
+    }
+    if let Some(f) = val.as_f64() {
+        let r = f as i32;
+        return (r, r);
+    }
+    if let Some(obj) = val.as_object() {
+        if let (Some(min), Some(max)) = (obj.get("min"), obj.get("max")) {
+            let min_r = min
+                .as_i64()
+                .or_else(|| min.as_f64().map(|f| f as i64))
+                .unwrap_or(1) as i32;
+            let max_r = max
+                .as_i64()
+                .or_else(|| max.as_f64().map(|f| f as i64))
+                .unwrap_or(min_r as i64) as i32;
+            return (min_r, max_r);
+        }
+        if let Some(value) = obj.get("value") {
+            let r = value
+                .as_i64()
+                .or_else(|| value.as_f64().map(|f| f as i64))
+                .unwrap_or(1) as i32;
+            return (r, r);
+        }
+        if let Some(n) = obj.get("n").and_then(Value::as_i64) {
+            return (0, n as i32);
+        }
+    }
+    (1, 1)
+}
+
+fn parse_entry(val: &Value, pool_entries: &mut Vec<DynamicLootEntry>, empty_weight: &mut i32) {
+    let entry_type = val
+        .get("type")
+        .and_then(Value::as_str)
+        .unwrap_or("minecraft:item");
+    let entry_type = entry_type.strip_prefix("minecraft:").unwrap_or(entry_type);
+    let weight = val.get("weight").and_then(Value::as_i64).unwrap_or(1) as i32;
+
+    match entry_type {
+        "empty" => {
+            *empty_weight += weight;
+        }
+        "item" | "tag" => {
+            if let Some(name) = val.get("name").and_then(Value::as_str) {
+                let (min_count, max_count, bonus_formula) =
+                    val.get("functions").map_or((1, 1, None), parse_functions);
+                let conditions = val.get("conditions").map_or(Vec::new(), parse_conditions);
+                let condition = combine_conditions(conditions);
+
+                pool_entries.push(DynamicLootEntry {
+                    item: name.to_string(),
+                    weight,
+                    min_count,
+                    max_count,
+                    condition,
+                    bonus_formula,
+                });
+            }
+        }
+        "alternatives" | "group" | "sequence" => {
+            if let Some(children) = val.get("children").and_then(Value::as_array) {
+                for child in children {
+                    parse_entry(child, pool_entries, empty_weight);
+                }
+            }
+        }
+        _ => {}
+    }
+}
+
+fn parse_functions(val: &Value) -> (i32, i32, Option<LootBonusFormula>) {
+    let mut min_count = 1;
+    let mut max_count = 1;
+    let mut bonus_formula = None;
+
+    let Some(functions) = val.as_array() else {
+        return (min_count, max_count, bonus_formula);
+    };
+
+    for func in functions {
+        let func_type = func
+            .get("function")
+            .and_then(Value::as_str)
+            .unwrap_or_default();
+        let func_type = func_type.strip_prefix("minecraft:").unwrap_or(func_type);
+
+        match func_type {
+            "set_count" => {
+                if let Some(count) = func.get("count") {
+                    let (min_c, max_c) = parse_rolls(count);
+                    min_count = min_c;
+                    max_count = max_c;
+                }
+            }
+            "apply_bonus" => {
+                if let Some(formula) = func.get("formula").and_then(Value::as_str) {
+                    let formula_clean = formula.strip_prefix("minecraft:").unwrap_or(formula);
+                    match formula_clean {
+                        "ore_drops" => {
+                            bonus_formula = Some(LootBonusFormula::OreDrops);
+                        }
+                        "uniform_bonus_count" => {
+                            let multiplier = func
+                                .get("parameters")
+                                .and_then(|p| p.get("bonusMultiplier"))
+                                .and_then(Value::as_i64)
+                                .unwrap_or(1) as i32;
+                            bonus_formula = Some(LootBonusFormula::UniformBonusCount(multiplier));
+                        }
+                        "binomial_with_bonus_count" => {
+                            let extra = func
+                                .get("parameters")
+                                .and_then(|p| p.get("extra"))
+                                .and_then(Value::as_i64)
+                                .unwrap_or(0) as i32;
+                            let probability =
+                                func.get("parameters")
+                                    .and_then(|p| p.get("probability"))
+                                    .and_then(Value::as_f64)
+                                    .unwrap_or(0.0) as f32;
+                            bonus_formula = Some(LootBonusFormula::BinomialWithBonusCount {
+                                extra,
+                                probability,
+                            });
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            "looting_enchant" => {
+                let max_bonus = func.get("count").map_or(1, |c| {
+                    c.get("max")
+                        .and_then(Value::as_i64)
+                        .or_else(|| c.as_i64())
+                        .unwrap_or(1) as i32
+                });
+                bonus_formula = Some(LootBonusFormula::UniformBonusCount(max_bonus.max(1)));
+            }
+            _ => {}
+        }
+    }
+
+    (min_count, max_count, bonus_formula)
+}
+
+fn parse_conditions(val: &Value) -> Vec<DynamicLootCondition> {
+    let Some(arr) = val.as_array() else {
+        return Vec::new();
+    };
+    arr.iter().map(parse_condition).collect()
+}
+
+fn parse_condition(val: &Value) -> DynamicLootCondition {
+    let cond_type = val
+        .get("condition")
+        .and_then(Value::as_str)
+        .unwrap_or_default();
+    let cond_type = cond_type.strip_prefix("minecraft:").unwrap_or(cond_type);
+
+    match cond_type {
+        "survives_explosion" => DynamicLootCondition::SurvivesExplosion,
+        "killed_by_player" => DynamicLootCondition::KilledByPlayer,
+        "random_chance" => {
+            let chance = val.get("chance").and_then(Value::as_f64).unwrap_or(1.0) as f32;
+            DynamicLootCondition::RandomChance { chance }
+        }
+        "random_chance_with_enchanted_bonus" => {
+            let unenchanted = val
+                .get("unenchanted_chance")
+                .and_then(Value::as_f64)
+                .unwrap_or(0.0) as f32;
+            let enchanted_base = val
+                .get("enchanted_chance")
+                .or_else(|| val.get("enchanted_chance_base"))
+                .and_then(Value::as_f64)
+                .unwrap_or(f64::from(unenchanted)) as f32;
+            let per_level = val
+                .get("enchanted_chance_per_level_above_first")
+                .and_then(Value::as_f64)
+                .unwrap_or(0.0) as f32;
+            DynamicLootCondition::RandomChanceWithEnchantedBonus {
+                unenchanted_chance: unenchanted,
+                enchanted_chance_base: enchanted_base,
+                enchanted_chance_per_level_above_first: per_level,
+            }
+        }
+        "table_bonus" => {
+            let chances: Vec<f32> = val
+                .get("chances")
+                .and_then(Value::as_array)
+                .map(|arr| {
+                    arr.iter()
+                        .filter_map(|x| x.as_f64().map(|f| f as f32))
+                        .collect()
+                })
+                .unwrap_or_default();
+            DynamicLootCondition::TableBonus {
+                chances: chances.into_boxed_slice(),
+            }
+        }
+        "inverted" => val.get("term").map_or(DynamicLootCondition::None, |term| {
+            DynamicLootCondition::Inverted(Box::new(parse_condition(term)))
+        }),
+        "any_of" => val
+            .get("terms")
+            .and_then(Value::as_array)
+            .map_or(DynamicLootCondition::None, |terms| {
+                DynamicLootCondition::AnyOf(terms.iter().map(parse_condition).collect())
+            }),
+        "all_of" => val
+            .get("terms")
+            .and_then(Value::as_array)
+            .map_or(DynamicLootCondition::None, |terms| {
+                DynamicLootCondition::AllOf(terms.iter().map(parse_condition).collect())
+            }),
+        "match_tool" => {
+            let pred_str = val
+                .get("predicate")
+                .map_or_else(String::new, Value::to_string);
+            let has_silk = pred_str.contains("silk_touch");
+            let has_shears = pred_str.contains("shears");
+            if has_silk && has_shears {
+                DynamicLootCondition::SilkTouchOrShears
+            } else if has_silk {
+                DynamicLootCondition::SilkTouch
+            } else if has_shears {
+                DynamicLootCondition::Shears
+            } else {
+                DynamicLootCondition::None
+            }
+        }
+        "entity_properties" => {
+            let on_fire = val
+                .get("predicate")
+                .and_then(|p| p.get("flags"))
+                .and_then(|f| f.get("is_on_fire"))
+                .and_then(Value::as_bool)
+                .unwrap_or(false);
+            if on_fire {
+                DynamicLootCondition::EntityOnFire
+            } else {
+                DynamicLootCondition::None
+            }
+        }
+        "weather_check" => {
+            let raining = val.get("raining").and_then(Value::as_bool);
+            let thundering = val.get("thundering").and_then(Value::as_bool);
+            DynamicLootCondition::WeatherCheck {
+                raining,
+                thundering,
+            }
+        }
+        _ => DynamicLootCondition::None,
+    }
+}
+
+fn combine_conditions(conditions: Vec<DynamicLootCondition>) -> DynamicLootCondition {
+    if conditions.is_empty() {
+        DynamicLootCondition::None
+    } else if conditions.len() == 1 {
+        conditions.into_iter().next().unwrap_or_default()
+    } else {
+        DynamicLootCondition::AllOf(conditions)
+    }
+}
+
+/// Loads all loot table JSON files from a directory recursively into `registry`.
+pub fn load_loot_tables_from_dir<S: std::hash::BuildHasher>(
+    namespace: &str,
+    dir: &Path,
+    registry: &mut HashMap<String, Arc<DynamicLootTable>, S>,
+) -> usize {
+    if !dir.is_dir() {
+        return 0;
+    }
+    let before = registry.len();
+    load_loot_tables_recursive(namespace, dir, dir, registry);
+    registry.len() - before
+}
+
+fn load_loot_tables_recursive<S: std::hash::BuildHasher>(
+    namespace: &str,
+    base_dir: &Path,
+    current_dir: &Path,
+    registry: &mut HashMap<String, Arc<DynamicLootTable>, S>,
+) {
+    let Ok(entries) = fs::read_dir(current_dir) else {
+        return;
+    };
+    for entry in entries.flatten() {
+        let path = entry.path();
+        if path.is_dir() {
+            load_loot_tables_recursive(namespace, base_dir, &path, registry);
+        } else if path
+            .extension()
+            .is_some_and(|ext| ext.eq_ignore_ascii_case("json"))
+            && let Ok(rel_path) = path.strip_prefix(base_dir)
+        {
+            let mut stem_path = rel_path.to_string_lossy().to_string();
+            if let Some(stem) = stem_path.strip_suffix(".json") {
+                stem_path = stem.to_string();
+            }
+            let stem_path = stem_path.replace('\\', "/");
+            let loot_table_id = format!("{namespace}:{stem_path}");
+
+            if let Ok(content) = fs::read_to_string(&path)
+                && let Some(table) = parse_loot_table(&content)
+            {
+                registry.insert(loot_table_id, Arc::new(table));
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_simple_loot_table() {
+        let json = r#"{
+            "type": "minecraft:chest",
+            "pools": [
+                {
+                    "rolls": 2,
+                    "entries": [
+                        {
+                            "type": "minecraft:item",
+                            "name": "minecraft:diamond",
+                            "weight": 5,
+                            "functions": [
+                                {
+                                    "function": "minecraft:set_count",
+                                    "count": {"min": 1, "max": 3}
+                                }
+                            ]
+                        },
+                        {
+                            "type": "minecraft:empty",
+                            "weight": 10
+                        }
+                    ]
+                }
+            ]
+        }"#;
+
+        let table = parse_loot_table(json).expect("valid loot table");
+        assert_eq!(table.pools.len(), 1);
+        let pool = &table.pools[0];
+        assert_eq!(pool.min_rolls, 2);
+        assert_eq!(pool.max_rolls, 2);
+        assert_eq!(pool.empty_weight, 10);
+        assert_eq!(pool.entries.len(), 1);
+        assert_eq!(pool.entries[0].item, "minecraft:diamond");
+        assert_eq!(pool.entries[0].weight, 5);
+        assert_eq!(pool.entries[0].min_count, 1);
+        assert_eq!(pool.entries[0].max_count, 3);
+    }
+
+    #[test]
+    fn parse_block_loot_with_silk_touch_and_fortune() {
+        let json = r#"{
+            "type": "minecraft:block",
+            "pools": [
+                {
+                    "rolls": 1,
+                    "entries": [
+                        {
+                            "type": "minecraft:alternatives",
+                            "children": [
+                                {
+                                    "type": "minecraft:item",
+                                    "name": "minecraft:coal_ore",
+                                    "conditions": [
+                                        {
+                                            "condition": "minecraft:match_tool",
+                                            "predicate": {
+                                                "predicates": {
+                                                    "minecraft:enchantments": [
+                                                        {"enchantments": "minecraft:silk_touch"}
+                                                    ]
+                                                }
+                                            }
+                                        }
+                                    ]
+                                },
+                                {
+                                    "type": "minecraft:item",
+                                    "name": "minecraft:coal",
+                                    "functions": [
+                                        {
+                                            "function": "minecraft:apply_bonus",
+                                            "formula": "minecraft:ore_drops"
+                                        }
+                                    ],
+                                    "conditions": [
+                                        {
+                                            "condition": "minecraft:survives_explosion"
+                                        }
+                                    ]
+                                }
+                            ]
+                        }
+                    ]
+                }
+            ]
+        }"#;
+
+        let table = parse_loot_table(json).expect("valid block loot table");
+        assert_eq!(table.pools.len(), 1);
+        let pool = &table.pools[0];
+        assert_eq!(pool.entries.len(), 2);
+        assert_eq!(pool.entries[0].item, "minecraft:coal_ore");
+        assert_eq!(pool.entries[0].condition, DynamicLootCondition::SilkTouch);
+        assert_eq!(pool.entries[1].item, "minecraft:coal");
+        assert_eq!(
+            pool.entries[1].bonus_formula,
+            Some(LootBonusFormula::OreDrops)
+        );
+        assert_eq!(
+            pool.entries[1].condition,
+            DynamicLootCondition::SurvivesExplosion
+        );
+    }
+
+    #[test]
+    fn directory_loading() {
+        let temp = tempfile::tempdir().expect("tempdir");
+        let root = temp.path();
+        let sub = root.join("blocks");
+        fs::create_dir_all(&sub).expect("create dir");
+
+        let table_json = r#"{
+            "pools": [
+                {
+                    "rolls": 1,
+                    "entries": [
+                        {
+                            "type": "minecraft:item",
+                            "name": "minecraft:dirt"
+                        }
+                    ]
+                }
+            ]
+        }"#;
+        fs::write(sub.join("dirt.json"), table_json).expect("write json");
+
+        let mut registry = HashMap::new();
+        let count = load_loot_tables_from_dir("custom", root, &mut registry);
+        assert_eq!(count, 1);
+        assert!(registry.contains_key("custom:blocks/dirt"));
+    }
+}

crates/pumpkin/src/data/datapack/mod.rs

@@ -1,4 +1,7 @@
+pub mod context_provider_loader;
+pub mod damage_type_loader;
 pub mod function_loader;
+pub mod loot_table_loader;
 pub mod recipe_loader;
 pub mod test_loader;
 
@@ -8,14 +11,20 @@ use std::path::{Path, PathBuf};
 use std::sync::{Arc, RwLock};
 use tracing::{info, warn};
 
+use pumpkin_data::damage::DamageType;
 use pumpkin_data::registry::RegistryEntryData;
+use pumpkin_nbt::tag::NbtTag;
 use pumpkin_nbt::{NbtCompound, nbt_compress::read_gzip_compound_tag};
 use pumpkin_protocol::codec::recipe::DynamicRecipe;
+use pumpkin_util::loot_table::DynamicLootTable;
 
 use crate::command::context::command_source::CommandSource;
 use crate::server::Server;
 use crate::server::recipe::RecipeManager;
+use crate::world::loot::LootTableHandle;
 
+use self::context_provider_loader::ContextProviderRegistry;
+use self::damage_type_loader::{DamageTypeDefinition, DamageTypeEntry, DamageTypeRegistry};
 use self::test_loader::{
     TestInstance, TestInstanceRegistry, load_test_instances_from_dir, to_registry_entry,
 };
@@ -63,6 +72,10 @@ pub struct DatapackManager {
     functions: RwLock<HashMap<String, Arc<[String]>>>,
     function_tags: RwLock<HashMap<String, Vec<String>>>,
     test_instances: RwLock<TestInstanceRegistry>,
+    context_int_providers: RwLock<ContextProviderRegistry>,
+    context_float_providers: RwLock<ContextProviderRegistry>,
+    damage_types: RwLock<DamageTypeRegistry>,
+    loot_tables: RwLock<HashMap<String, Arc<DynamicLootTable>>>,
 }
 
 fn share_function_bodies(
@@ -88,6 +101,10 @@ impl DatapackManager {
             functions: RwLock::new(HashMap::new()),
             function_tags: RwLock::new(HashMap::new()),
             test_instances: RwLock::new(HashMap::new()),
+            context_int_providers: RwLock::new(HashMap::new()),
+            context_float_providers: RwLock::new(HashMap::new()),
+            damage_types: RwLock::new(HashMap::new()),
+            loot_tables: RwLock::new(HashMap::new()),
         }
     }
 
@@ -103,6 +120,10 @@ impl DatapackManager {
         let mut all_functions: HashMap<String, Vec<String>> = HashMap::new();
         let mut all_function_tags: HashMap<String, Vec<String>> = HashMap::new();
         let mut all_test_instances: TestInstanceRegistry = HashMap::new();
+        let mut all_context_int_providers: ContextProviderRegistry = HashMap::new();
+        let mut all_context_float_providers: ContextProviderRegistry = HashMap::new();
+        let mut all_damage_type_defs: HashMap<String, DamageTypeDefinition> = HashMap::new();
+        let mut all_loot_tables: HashMap<String, Arc<DynamicLootTable>> = HashMap::new();
 
         // Embedded test instances are compile-time constants and always load,
         // so on-disk packs can override them by id.
@@ -110,60 +131,25 @@ impl DatapackManager {
         if embedded_count > 0 {
             info!("Loaded {embedded_count} embedded test instance(s)");
         }
-        if datapacks_dir.is_dir() {
-            match fs::read_dir(&datapacks_dir) {
-                Ok(entries) => {
-                    for entry in entries.flatten() {
-                        let pack_path = entry.path();
-                        let file_name = entry.file_name().to_string_lossy().to_string();
+        let mut acc = PackContentAccumulators {
+            recipes: &mut all_recipes,
+            functions: &mut all_functions,
+            function_tags: &mut all_function_tags,
+            test_instances: &mut all_test_instances,
+            damage_types: &mut all_damage_type_defs,
+            context_int_providers: &mut all_context_int_providers,
+            context_float_providers: &mut all_context_float_providers,
+            loot_tables: &mut all_loot_tables,
+        };
 
-                        if file_name.starts_with('.') || !pack_path.is_dir() {
-                            continue;
-                        }
-
-                        let pack_id = format!("file/{file_name}");
-                        let is_enabled = enabled_packs
-                            .iter()
-                            .any(|p| p == &pack_id || p == &file_name);
-                        if !is_enabled {
-                            continue;
-                        }
-
-                        let (description, pack_format, known_packs) = read_pack_mcmeta(&pack_path);
-
-                        let (pack_recipe_count, pack_function_count, pack_test_instance_count) =
-                            load_pack_contents(
-                                &pack_path,
-                                &mut all_recipes,
-                                &mut all_functions,
-                                &mut all_function_tags,
-                                &mut all_test_instances,
+        scan_datapacks_dir(
+            &datapacks_dir,
+            enabled_packs,
+            &mut acc,
+            &mut loaded_packs_vec,
         );
 
-                        info!(
-                            "Loaded datapack '{file_name}': {pack_recipe_count} recipe(s), {pack_function_count} function(s), {pack_test_instance_count} test instance(s)"
-                        );
-
-                        loaded_packs_vec.push(LoadedDatapack {
-                            id: pack_id,
-                            name: file_name,
-                            description,
-                            pack_format,
-                            root_path: pack_path,
-                            recipe_count: pack_recipe_count,
-                            function_count: pack_function_count,
-                            known_packs,
-                        });
-                    }
-                }
-                Err(error) => {
-                    warn!(
-                        "Failed to read datapacks directory '{}': {error}",
-                        datapacks_dir.display()
-                    );
-                }
-            }
-        }
+        let damage_type_registry = build_damage_type_registry(all_damage_type_defs);
 
         recipe_manager.set_recipes(all_recipes);
         *self
@@ -183,6 +169,22 @@ impl DatapackManager {
             .test_instances
             .write()
             .unwrap_or_else(std::sync::PoisonError::into_inner) = all_test_instances;
+        *self
+            .context_int_providers
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner) = all_context_int_providers;
+        *self
+            .context_float_providers
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner) = all_context_float_providers;
+        *self
+            .damage_types
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner) = damage_type_registry;
+        *self
+            .loot_tables
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner) = all_loot_tables;
     }
 
     pub fn get_loaded_packs(&self) -> Vec<LoadedDatapack> {
@@ -219,6 +221,162 @@ impl DatapackManager {
         names
     }
 
+    #[must_use]
+    pub fn get_context_int_provider(&self, id: &str) -> Option<NbtTag> {
+        self.context_int_providers
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .get(id)
+            .cloned()
+    }
+
+    #[must_use]
+    pub fn get_context_float_provider(&self, id: &str) -> Option<NbtTag> {
+        self.context_float_providers
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .get(id)
+            .cloned()
+    }
+
+    #[must_use]
+    pub fn get_context_int_provider_names(&self) -> Vec<String> {
+        let providers = self
+            .context_int_providers
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let mut names: Vec<_> = providers.keys().cloned().collect();
+        names.sort_unstable();
+        names
+    }
+
+    #[must_use]
+    pub fn get_context_float_provider_names(&self) -> Vec<String> {
+        let providers = self
+            .context_float_providers
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let mut names: Vec<_> = providers.keys().cloned().collect();
+        names.sort_unstable();
+        names
+    }
+
+    pub fn insert_context_int_provider(&self, id: String, tag: NbtTag) {
+        self.context_int_providers
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .insert(id, tag);
+    }
+
+    pub fn insert_context_float_provider(&self, id: String, tag: NbtTag) {
+        self.context_float_providers
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .insert(id, tag);
+    }
+
+    #[must_use]
+    pub fn get_loot_table(&self, key: &str) -> Option<LootTableHandle> {
+        let full_key = if key.contains(':') {
+            key.to_string()
+        } else {
+            format!("minecraft:{key}")
+        };
+
+        let guard = self
+            .loot_tables
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+
+        if let Some(table) = guard.get(&full_key).or_else(|| guard.get(key)) {
+            return Some(LootTableHandle::Dynamic(table.clone()));
+        }
+
+        pumpkin_data::loot_table::get_loot_table(key)
+            .or_else(|| pumpkin_data::loot_table::get_loot_table(&full_key))
+            .map(LootTableHandle::Static)
+    }
+
+    #[must_use]
+    pub fn get_loot_table_names(&self) -> Vec<String> {
+        let guard = self
+            .loot_tables
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let mut names: Vec<_> = guard.keys().cloned().collect();
+        names.sort_unstable();
+        names
+    }
+
+    pub fn insert_loot_table(&self, key: String, table: Arc<DynamicLootTable>) {
+        self.loot_tables
+            .write()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .insert(key, table);
+    }
+
+    #[must_use]
+    pub fn get_damage_type(&self, id: &str) -> Option<DamageType> {
+        let guard = self
+            .damage_types
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let full_id = if id.contains(':') {
+            id.to_string()
+        } else {
+            format!("minecraft:{id}")
+        };
+        guard
+            .get(&full_id)
+            .or_else(|| guard.get(id))
+            .map(|e| e.damage_type)
+    }
+
+    #[must_use]
+    pub fn get_damage_type_names(&self) -> Vec<String> {
+        let guard = self
+            .damage_types
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let mut names: Vec<_> = guard.keys().cloned().collect();
+        names.sort_unstable();
+        names
+    }
+
+    #[must_use]
+    pub fn get_damage_type_registry_map(&self) -> HashMap<String, DamageTypeEntry> {
+        self.damage_types
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .clone()
+    }
+
+    #[must_use]
+    pub fn get_all_damage_type_registry_entries(&self) -> Vec<RegistryEntryData> {
+        let guard = self
+            .damage_types
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let mut entries: Vec<RegistryEntryData> = guard
+            .values()
+            .map(DamageTypeEntry::to_registry_entry)
+            .collect();
+        entries.sort_by(|a, b| a.entry_id.cmp(&b.entry_id));
+        entries
+    }
+
+    #[must_use]
+    pub fn merge_damage_type_entries(
+        &self,
+        vanilla_entries: &[RegistryEntryData],
+    ) -> Vec<RegistryEntryData> {
+        let guard = self
+            .damage_types
+            .read()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        merge_damage_type_entries(vanilla_entries, &guard)
+    }
+
     /// Returns datapack test instances in the protocol's synced-registry entry format.
     /// The vanilla Test Instance Block renderer resolves required/padding/base rotation
     /// through this registry using the controller's `data.test` resource key.
@@ -868,19 +1026,153 @@ fn parse_structure_resource_location(resource_location: &str) -> Result<(&str, &
     Ok((namespace, path))
 }
 
-/// Loads recipes, functions, function tags, and test instances from a single
-/// datapack directory, returning per-pack counts as `(recipes, functions, test_instances)`.
+fn build_damage_type_registry(
+    mut all_damage_type_defs: HashMap<String, DamageTypeDefinition>,
+) -> DamageTypeRegistry {
+    let mut damage_type_registry: DamageTypeRegistry = HashMap::new();
+    let mut next_custom_id = 51u8;
+    let mut static_map: HashMap<String, &'static DamageType> = HashMap::new();
+    let mut names = Vec::new();
+
+    let mut sorted_ids: Vec<String> = all_damage_type_defs.keys().cloned().collect();
+    sorted_ids.sort();
+
+    for id in sorted_ids {
+        let Some(def) = all_damage_type_defs.remove(&id) else {
+            continue;
+        };
+        let path = id.split_once(':').map_or(id.as_str(), |(_, p)| p);
+        let numeric_id = pumpkin_data::damage::DamageType::from_name(path)
+            .or_else(|| pumpkin_data::damage::DamageType::from_name(&id))
+            .map_or_else(
+                || {
+                    let nid = next_custom_id;
+                    next_custom_id = next_custom_id.saturating_add(1);
+                    nid
+                },
+                |vanilla_dt| vanilla_dt.id,
+            );
+
+        let dt = damage_type_loader::to_damage_type(numeric_id, &def);
+        let nbt_data = damage_type_loader::to_registry_nbt_bytes(&def);
+        let leaked_dt = Box::leak(Box::new(dt));
+        static_map.insert(id.clone(), leaked_dt);
+        static_map.insert(path.to_string(), leaked_dt);
+        names.push(id.clone());
+
+        damage_type_registry.insert(
+            id.clone(),
+            DamageTypeEntry {
+                id,
+                numeric_id,
+                definition: def,
+                damage_type: dt,
+                nbt_data,
+            },
+        );
+    }
+
+    pumpkin_command::argument_types::resource::register_dynamic_damage_types(
+        Box::new(move |req_id: &str| static_map.get(req_id).copied()),
+        names,
+    );
+
+    damage_type_registry
+}
+
+struct PackContentAccumulators<'a> {
+    recipes: &'a mut Vec<DynamicRecipe>,
+    functions: &'a mut HashMap<String, Vec<String>>,
+    function_tags: &'a mut HashMap<String, Vec<String>>,
+    test_instances: &'a mut TestInstanceRegistry,
+    damage_types: &'a mut HashMap<String, DamageTypeDefinition>,
+    context_int_providers: &'a mut ContextProviderRegistry,
+    context_float_providers: &'a mut ContextProviderRegistry,
+    loot_tables: &'a mut HashMap<String, Arc<DynamicLootTable>>,
+}
+
+#[derive(Default, Clone, Copy)]
+struct PackContentCounts {
+    recipes: usize,
+    functions: usize,
+    test_instances: usize,
+    damage_types: usize,
+    int_providers: usize,
+    float_providers: usize,
+    loot_tables: usize,
+}
+
+fn scan_datapacks_dir(
+    datapacks_dir: &Path,
+    enabled_packs: &[String],
+    acc: &mut PackContentAccumulators<'_>,
+    loaded_packs_vec: &mut Vec<LoadedDatapack>,
+) {
+    if !datapacks_dir.is_dir() {
+        return;
+    }
+    let entries = match fs::read_dir(datapacks_dir) {
+        Ok(entries) => entries,
+        Err(error) => {
+            warn!(
+                "Failed to read datapacks directory '{}': {error}",
+                datapacks_dir.display()
+            );
+            return;
+        }
+    };
+
+    for entry in entries.flatten() {
+        let pack_path = entry.path();
+        let file_name = entry.file_name().to_string_lossy().to_string();
+
+        if file_name.starts_with('.') || !pack_path.is_dir() {
+            continue;
+        }
+
+        let pack_id = format!("file/{file_name}");
+        let is_enabled = enabled_packs
+            .iter()
+            .any(|p| p == &pack_id || p == &file_name);
+        if !is_enabled {
+            continue;
+        }
+
+        let (description, pack_format, known_packs) = read_pack_mcmeta(&pack_path);
+        let counts = load_pack_contents(&pack_path, acc);
+
+        info!(
+            "Loaded datapack '{file_name}': {} recipe(s), {} function(s), {} test instance(s), {} damage type(s), {} int provider(s), {} float provider(s), {} loot table(s)",
+            counts.recipes,
+            counts.functions,
+            counts.test_instances,
+            counts.damage_types,
+            counts.int_providers,
+            counts.float_providers,
+            counts.loot_tables,
+        );
+
+        loaded_packs_vec.push(LoadedDatapack {
+            id: pack_id,
+            name: file_name,
+            description,
+            pack_format,
+            root_path: pack_path,
+            recipe_count: counts.recipes,
+            function_count: counts.functions,
+            known_packs,
+        });
+    }
+}
+
+/// Loads recipes, functions, function tags, test instances, damage types, context number providers,
+/// and loot tables from a single datapack directory, returning per-pack counts as [`PackContentCounts`].
 fn load_pack_contents(
     pack_path: &Path,
-    all_recipes: &mut Vec<DynamicRecipe>,
-    all_functions: &mut HashMap<String, Vec<String>>,
-    all_function_tags: &mut HashMap<String, Vec<String>>,
-    all_test_instances: &mut TestInstanceRegistry,
-) -> (usize, usize, usize) {
+    acc: &mut PackContentAccumulators<'_>,
+) -> PackContentCounts {
     let data_dir = pack_path.join("data");
-    let mut pack_recipe_count = 0;
-    let mut pack_function_count = 0;
-    let mut pack_test_instance_count = 0;
+    let mut counts = PackContentCounts::default();
 
     if data_dir.is_dir()
         && let Ok(ns_entries) = fs::read_dir(&data_dir)
@@ -899,8 +1191,8 @@ fn load_pack_contents(
                     load_recipes_from_dir(
                         &namespace,
                         &recipe_dir,
-                        all_recipes,
-                        &mut pack_recipe_count,
+                        acc.recipes,
+                        &mut counts.recipes,
                     );
                 }
             }
@@ -909,9 +1201,9 @@ fn load_pack_contents(
             for fn_sub in ["function", "functions"] {
                 let fn_dir = ns_path.join(fn_sub);
                 if fn_dir.is_dir() {
-                    let before = all_functions.len();
-                    function_loader::load_functions_from_dir(&namespace, &fn_dir, all_functions);
-                    pack_function_count += all_functions.len() - before;
+                    let before = acc.functions.len();
+                    function_loader::load_functions_from_dir(&namespace, &fn_dir, acc.functions);
+                    counts.functions += acc.functions.len() - before;
                 }
             }
 
@@ -921,26 +1213,126 @@ fn load_pack_contents(
                 function_loader::load_function_tags_from_dir(
                     &namespace,
                     &tags_dir,
-                    all_function_tags,
+                    acc.function_tags,
                 );
             }
             // Load game test instances
             let test_instance_dir = ns_path.join("test_instance");
             if test_instance_dir.is_dir() {
-                pack_test_instance_count += load_test_instances_from_dir(
+                counts.test_instances += load_test_instances_from_dir(
                     &namespace,
                     &test_instance_dir,
-                    all_test_instances,
+                    acc.test_instances,
+                );
+            }
+
+            // Load damage types
+            for dt_sub in ["damage_type", "damage_types"] {
+                let dt_dir = ns_path.join(dt_sub);
+                if dt_dir.is_dir() {
+                    counts.damage_types += damage_type_loader::load_damage_types_from_dir(
+                        &namespace,
+                        &dt_dir,
+                        acc.damage_types,
+                    );
+                }
+            }
+
+            // Load context int providers
+            for int_sub in ["context_int_provider", "context_int_providers"] {
+                let provider_dir = ns_path.join(int_sub);
+                if provider_dir.is_dir() {
+                    counts.int_providers +=
+                        context_provider_loader::load_context_providers_from_dir(
+                            &namespace,
+                            &provider_dir,
+                            acc.context_int_providers,
+                        );
+                }
+            }
+
+            // Load context float providers
+            for float_sub in ["context_float_provider", "context_float_providers"] {
+                let provider_dir = ns_path.join(float_sub);
+                if provider_dir.is_dir() {
+                    counts.float_providers +=
+                        context_provider_loader::load_context_providers_from_dir(
+                            &namespace,
+                            &provider_dir,
+                            acc.context_float_providers,
+                        );
+                }
+            }
+
+            // Load loot tables
+            for lt_sub in ["loot_table", "loot_tables"] {
+                let lt_dir = ns_path.join(lt_sub);
+                if lt_dir.is_dir() {
+                    counts.loot_tables += loot_table_loader::load_loot_tables_from_dir(
+                        &namespace,
+                        &lt_dir,
+                        acc.loot_tables,
                     );
                 }
             }
         }
+    }
 
-    (
-        pack_recipe_count,
-        pack_function_count,
-        pack_test_instance_count,
-    )
+    counts
+}
+
+#[must_use]
+pub fn clone_registry_entry(entry: &RegistryEntryData) -> RegistryEntryData {
+    RegistryEntryData {
+        entry_id: entry.entry_id.clone(),
+        data: entry.data.clone(),
+    }
+}
+
+#[must_use]
+pub fn merge_damage_type_entries<S: std::hash::BuildHasher>(
+    vanilla_entries: &[RegistryEntryData],
+    custom_entries: &HashMap<String, DamageTypeEntry, S>,
+) -> Vec<RegistryEntryData> {
+    if custom_entries.is_empty() {
+        return vanilla_entries.iter().map(clone_registry_entry).collect();
+    }
+
+    let mut merged = Vec::with_capacity(vanilla_entries.len() + custom_entries.len());
+    let mut overridden = std::collections::HashSet::new();
+
+    for entry in vanilla_entries {
+        let full_id = if entry.entry_id.contains(':') {
+            entry.entry_id.clone()
+        } else {
+            format!("minecraft:{}", entry.entry_id)
+        };
+
+        if let Some(custom) = custom_entries
+            .get(&full_id)
+            .or_else(|| custom_entries.get(&entry.entry_id))
+        {
+            let mut reg_entry = custom.to_registry_entry();
+            reg_entry.entry_id.clone_from(&entry.entry_id);
+            merged.push(reg_entry);
+            overridden.insert(full_id);
+            overridden.insert(entry.entry_id.clone());
+        } else {
+            merged.push(clone_registry_entry(entry));
+        }
+    }
+
+    let mut sorted_custom: Vec<&DamageTypeEntry> = custom_entries
+        .values()
+        .filter(|e| !overridden.contains(&e.id))
+        .collect();
+    sorted_custom.sort_by_key(|e| e.numeric_id);
+
+    for custom in sorted_custom {
+        merged.push(custom.to_registry_entry());
+    }
+
+    merged
 }
 
 fn read_pack_mcmeta(pack_path: &Path) -> (String, u32, Vec<KnownPackData>) {

crates/pumpkin/src/entity/living.rs

@@ -2273,11 +2273,12 @@ impl LivingEntity {
     fn drop_loot(&self, params: &LootContextParameters) {
         let resource_name = self.get_entity().entity_type.resource_name;
         let key = format!("minecraft:entities/{resource_name}");
-        if let Some(loot_table) = pumpkin_data::loot_table::get_loot_table(&key) {
+        let world = self.entity.world.load();
+        if let Some(loot_table) = world.get_loot_table(&key) {
             let seed: i64 = rand::random();
             let pos = self.entity.block_pos.load();
-            for stack in crate::world::loot::generate_loot_with_context(loot_table, seed, params) {
-                self.entity.world.load().drop_stack(&pos, stack);
+            for stack in crate::world::loot::generate_loot_from_handle(&loot_table, seed, params) {
+                world.drop_stack(&pos, stack);
             }
         }
     }

crates/pumpkin/src/entity/vehicle/minecart/container.rs

@@ -15,8 +15,6 @@ use pumpkin_util::math::vector3::Vector3;
 use pumpkin_util::text::TextComponent;
 
 use crate::entity::{Entity, player::Player};
-use crate::world::loot::fill_chest_inventory;
-use pumpkin_data::loot_table::get_loot_table;
 
 pub(super) struct MinecartInventory {
     items: RwLock<Vec<ItemStack>>,
@@ -98,7 +96,7 @@ impl MinecartInventory {
         let Some((loot_table, seed)) = loot_table else {
             return;
         };
-        let Some(table) = get_loot_table(&loot_table) else {
+        let Some(table) = crate::world::loot::get_loot_table(&loot_table) else {
             *self
                 .loot_table
                 .lock()
@@ -107,7 +105,7 @@ impl MinecartInventory {
         };
 
         let inventory: Arc<dyn Inventory> = self.clone();
-        fill_chest_inventory(&inventory, table, seed);
+        crate::world::loot::fill_chest_inventory_handle(&inventory, &table, seed);
     }
 }
 

crates/pumpkin/src/item/items/brush.rs

@@ -43,8 +43,8 @@ fn get_archaeology_loot(is_sand: bool, location: BlockPos, world: &World) -> Ite
         "minecraft:archaeology/trail_ruins_common"
     };
 
-    if let Some(table) = pumpkin_data::loot_table::get_loot_table(loot_key) {
-        let items = crate::world::loot::generate_loot(table, rand::random());
+    if let Some(table) = world.get_loot_table(loot_key) {
+        let items = table.generate_loot(rand::random());
         if let Some(first) = items.into_iter().next() {
             return first;
         }

crates/pumpkin/src/item/items/hoe.rs

@@ -50,10 +50,10 @@ impl ItemBehaviour for HoeItem {
             world.set_block_state(&location, result.new_state_id, BlockFlags::NOTIFY_ALL);
 
             if let Some(loot_key) = result.entry.loot
-                && let Some(loot_table) = pumpkin_data::loot_table::get_loot_table(loot_key)
+                && let Some(loot_table) = world.get_loot_table(loot_key)
             {
                 let seed = rand::random::<i64>();
-                let drops = crate::world::loot::generate_loot(loot_table, seed);
+                let drops = loot_table.generate_loot(seed);
                 for drop_stack in drops {
                     if result.entry.drop_strategy == Some(DropStrategy::ClickedFace) {
                         world.drop_stack_from_face(&location, face, drop_stack);

crates/pumpkin/src/net/java/config/known_packs.rs

@@ -1,5 +1,7 @@
 #[allow(clippy::wildcard_imports)]
 use super::*;
+use bytes::Bytes;
+use std::collections::HashMap;
 
 impl JavaClient {
     pub async fn handle_known_packs(&self, server: &Server) -> Option<PacketHandlerResult> {
@@ -15,12 +17,48 @@ impl JavaClient {
 
             let test_instance_entries =
                 server.datapack_manager.get_test_instance_registry_entries();
+            let custom_damage_type_map = server.datapack_manager.get_damage_type_registry_map();
 
             let packets = tokio::task::spawn_blocking(move || {
+                Self::build_synced_registry_packets(
+                    version,
+                    &test_instance_entries,
+                    &custom_damage_type_map,
+                )
+            })
+            .await
+            .unwrap_or_default();
+
+            for packet_data in packets {
+                self.send_packet_now(packet_data).await;
+            }
+        }
+
+        // We are done with configuring
+        self.send_packet(&CFinishConfig).await;
+
+        if !version.supports_configuration_state() {
+            return Some(self.handle_config_acknowledged(server).await);
+        }
+
+        debug!("Finished config");
+        None
+    }
+
+    fn build_synced_registry_packets<S: std::hash::BuildHasher>(
+        version: JavaMinecraftVersion,
+        test_instance_entries: &[pumpkin_data::registry::RegistryEntryData],
+        custom_damage_type_map: &HashMap<
+            String,
+            crate::data::datapack::damage_type_loader::DamageTypeEntry,
+            S,
+        >,
+    ) -> Vec<Bytes> {
         let registry = Registry::get_synced(version);
         let mut packets = Vec::new();
         let mut sent_dimension_type = false;
         let mut sent_test_instance = false;
+        let mut sent_damage_type = false;
 
         for reg in &registry {
             if reg.registry_id == "minecraft:dimension_type" {
@@ -30,7 +68,24 @@ impl JavaClient {
             if reg.registry_id == "minecraft:test_instance" {
                 sent_test_instance = true;
 
-                        let packet = CRegistryData::new(&reg.registry_id, &test_instance_entries);
+                let packet = CRegistryData::new(&reg.registry_id, test_instance_entries);
+
+                if let Ok(data) = Self::serialize_packet_for_version(&packet, version) {
+                    packets.push(data);
+                }
+
+                continue;
+            }
+
+            if reg.registry_id == "minecraft:damage_type" {
+                sent_damage_type = true;
+
+                let merged_damage_types = crate::data::datapack::merge_damage_type_entries(
+                    &reg.registry_entries,
+                    custom_damage_type_map,
+                );
+
+                let packet = CRegistryData::new(&reg.registry_id, &merged_damage_types);
 
                 if let Ok(data) = Self::serialize_packet_for_version(&packet, version) {
                     packets.push(data);
@@ -51,7 +106,18 @@ impl JavaClient {
         // client, so always provide it even when the static table omitted it.
         if !sent_test_instance {
             let test_instance = "minecraft:test_instance".to_string();
-                    let packet = CRegistryData::new(&test_instance, &test_instance_entries);
+            let packet = CRegistryData::new(&test_instance, test_instance_entries);
+
+            if let Ok(data) = Self::serialize_packet_for_version(&packet, version) {
+                packets.push(data);
+            }
+        }
+
+        if !sent_damage_type && !custom_damage_type_map.is_empty() {
+            let damage_type = "minecraft:damage_type".to_string();
+            let merged_damage_types =
+                crate::data::datapack::merge_damage_type_entries(&[], custom_damage_type_map);
+            let packet = CRegistryData::new(&damage_type, &merged_damage_types);
 
             if let Ok(data) = Self::serialize_packet_for_version(&packet, version) {
                 packets.push(data);
@@ -59,21 +125,7 @@ impl JavaClient {
         }
 
         if !sent_dimension_type {
-                    let dims = [
-                        &pumpkin_data::dimension::Dimension::OVERWORLD,
-                        &pumpkin_data::dimension::Dimension::OVERWORLD_CAVES,
-                        &pumpkin_data::dimension::Dimension::THE_END,
-                        &pumpkin_data::dimension::Dimension::THE_NETHER,
-                    ];
-
-                    let dim_entries: Vec<pumpkin_data::registry::RegistryEntryData> = dims
-                        .iter()
-                        .map(|dim| pumpkin_data::registry::RegistryEntryData {
-                            entry_id: dim.minecraft_name.to_string(),
-                            data: Some(build_dimension_nbt(dim).into_boxed_slice()),
-                        })
-                        .collect();
-
+            let dim_entries = get_fallback_dimension_type_entries();
             let dim_type = "minecraft:dimension_type".to_string();
             let packet = CRegistryData::new(&dim_type, &dim_entries);
 
@@ -82,16 +134,7 @@ impl JavaClient {
             }
         }
 
-                let mut tags = Vec::new();
-
-                for &key in pumpkin_data::tag::RegistryKey::NETWORK_KEYS {
-                    if pumpkin_data::tag::get_registry_key_tags(version, key)
-                        .is_some_and(|map| !map.is_empty())
-                    {
-                        tags.push(key);
-                    }
-                }
-
+        let tags = get_network_tag_keys(version);
         let packet = CUpdateTags::new(&tags);
 
         if let Ok(data) = Self::serialize_packet_for_version(&packet, version) {
@@ -99,23 +142,34 @@ impl JavaClient {
         }
 
         packets
-            })
-            .await
-            .unwrap_or_default();
-
-            for packet_data in packets {
-                self.send_packet_now(packet_data).await;
-            }
-        }
-
-        // We are done with configuring
-        self.send_packet(&CFinishConfig).await;
-
-        if !version.supports_configuration_state() {
-            return Some(self.handle_config_acknowledged(server).await);
-        }
-
-        debug!("Finished config");
-        None
     }
 }
+
+fn get_fallback_dimension_type_entries() -> Vec<pumpkin_data::registry::RegistryEntryData> {
+    let dims = [
+        &pumpkin_data::dimension::Dimension::OVERWORLD,
+        &pumpkin_data::dimension::Dimension::OVERWORLD_CAVES,
+        &pumpkin_data::dimension::Dimension::THE_END,
+        &pumpkin_data::dimension::Dimension::THE_NETHER,
+    ];
+
+    dims.iter()
+        .map(|dim| pumpkin_data::registry::RegistryEntryData {
+            entry_id: dim.minecraft_name.to_string(),
+            data: Some(build_dimension_nbt(dim).into_boxed_slice()),
+        })
+        .collect()
+}
+
+fn get_network_tag_keys(version: JavaMinecraftVersion) -> Vec<pumpkin_data::tag::RegistryKey> {
+    let mut tags = Vec::new();
+
+    for &key in pumpkin_data::tag::RegistryKey::NETWORK_KEYS {
+        if pumpkin_data::tag::get_registry_key_tags(version, key).is_some_and(|map| !map.is_empty())
+        {
+            tags.push(key);
+        }
+    }
+
+    tags
+}

crates/pumpkin/src/net/java/login/known_packs.rs

@@ -11,6 +11,14 @@ impl PendingConnection {
             }
             let registry = pumpkin_data::registry::Registry::get_synced(version);
             for reg in &registry {
+                if reg.registry_id == "minecraft:damage_type" {
+                    let merged = server
+                        .datapack_manager
+                        .merge_damage_type_entries(&reg.registry_entries);
+                    self.send_packet_now(&CRegistryData::new(&reg.registry_id, &merged))
+                        .await;
+                    continue;
+                }
                 self.send_packet_now(&CRegistryData::new(&reg.registry_id, &reg.registry_entries))
                     .await;
             }

crates/pumpkin/src/world/loot.rs

@@ -3,7 +3,10 @@ use pumpkin_data::damage::DamageType;
 use pumpkin_data::entity::EntityType;
 use pumpkin_data::item::Item;
 use pumpkin_data::item_stack::ItemStack;
-use pumpkin_util::loot_table::{LootBonusFormula, LootCondition, LootEntry, LootTable};
+pub use pumpkin_util::loot_table::{
+    DynamicLootCondition, DynamicLootEntry, DynamicLootPool, DynamicLootTable, LootBonusFormula,
+    LootCondition, LootEntry, LootPool, LootTable,
+};
 use pumpkin_util::random::{RandomImpl, xoroshiro128::Xoroshiro};
 
 #[derive(Default, Clone)]
@@ -26,6 +29,74 @@ pub struct LootContextParameters {
     pub is_on_fire: Option<bool>,
 }
 
+fn check_dynamic_condition(
+    cond: &DynamicLootCondition,
+    has_silk_touch: bool,
+    has_shears: bool,
+    fortune_level: i32,
+    params: &LootContextParameters,
+    rng: &mut Xoroshiro,
+) -> bool {
+    match cond {
+        DynamicLootCondition::None => true,
+        DynamicLootCondition::SilkTouch => has_silk_touch,
+        DynamicLootCondition::NoSilkTouch => !has_silk_touch,
+        DynamicLootCondition::Shears => has_shears,
+        DynamicLootCondition::SilkTouchOrShears => has_silk_touch || has_shears,
+        DynamicLootCondition::NoSilkTouchOrShears => !has_silk_touch && !has_shears,
+        DynamicLootCondition::KilledByPlayer => params.killed_by_player.unwrap_or(false),
+        DynamicLootCondition::SurvivesExplosion => params
+            .explosion_radius
+            .is_none_or(|radius| rng.next_f32() <= 1.0 / radius),
+        DynamicLootCondition::RandomChance { chance } => rng.next_f32() < *chance,
+        DynamicLootCondition::RandomChanceWithEnchantedBonus {
+            unenchanted_chance,
+            enchanted_chance_base,
+            enchanted_chance_per_level_above_first,
+        } => {
+            let chance = if fortune_level > 0 {
+                enchanted_chance_base
+                    + enchanted_chance_per_level_above_first * (fortune_level - 1) as f32
+            } else {
+                *unenchanted_chance
+            };
+            rng.next_f32() < chance
+        }
+        DynamicLootCondition::TableBonus { chances } => {
+            let index = (fortune_level.max(0) as usize).min(chances.len().saturating_sub(1));
+            chances
+                .get(index)
+                .is_some_and(|chance| rng.next_f32() < *chance)
+        }
+        DynamicLootCondition::AllOf(conditions) => conditions.iter().all(|c| {
+            check_dynamic_condition(c, has_silk_touch, has_shears, fortune_level, params, rng)
+        }),
+        DynamicLootCondition::AnyOf(conditions) => conditions.iter().any(|c| {
+            check_dynamic_condition(c, has_silk_touch, has_shears, fortune_level, params, rng)
+        }),
+        DynamicLootCondition::Inverted(cond) => {
+            !check_dynamic_condition(cond, has_silk_touch, has_shears, fortune_level, params, rng)
+        }
+        DynamicLootCondition::EntityOnFire => params.is_on_fire.unwrap_or(false),
+        DynamicLootCondition::WeatherCheck {
+            raining,
+            thundering,
+        } => {
+            if let Some(r) = raining
+                && params.is_raining != Some(*r)
+            {
+                return false;
+            }
+            if let Some(t) = thundering
+                && params.is_thundering != Some(*t)
+            {
+                return false;
+            }
+            true
+        }
+    }
+}
+
 fn check_condition(
     cond: LootCondition,
     has_silk_touch: bool,
@@ -232,13 +303,207 @@ pub fn generate_loot_with_context(
 
 pub use generate_loot as generate_chest_loot;
 
-pub fn fill_chest_inventory(
+#[must_use]
+pub fn generate_dynamic_loot(table: &DynamicLootTable, seed: i64) -> Vec<ItemStack> {
+    generate_dynamic_loot_with_context(table, seed, &LootContextParameters::default())
+}
+
+#[must_use]
+pub fn generate_dynamic_loot_with_context(
+    table: &DynamicLootTable,
+    seed: i64,
+    params: &LootContextParameters,
+) -> Vec<ItemStack> {
+    let mut rng = Xoroshiro::from_seed(seed as u64);
+    let mut items_to_place: Vec<ItemStack> = Vec::new();
+
+    let has_silk_touch = params.tool.as_ref().is_some_and(|tool| {
+        pumpkin_data::Enchantment::from_name("silk_touch")
+            .is_some_and(|e| tool.get_enchantment_level(e) > 0)
+    });
+
+    let has_shears = params.tool.as_ref().is_some_and(|tool| {
+        let name = tool
+            .item
+            .registry_key
+            .strip_prefix("minecraft:")
+            .unwrap_or(tool.item.registry_key);
+        name == "shears"
+    });
+
+    let fortune_level = params.tool.as_ref().map_or(0, |tool| {
+        let fortune = pumpkin_data::Enchantment::from_name("fortune")
+            .map_or(0, |e| tool.get_enchantment_level(e));
+        let looting = pumpkin_data::Enchantment::from_name("looting")
+            .map_or(0, |e| tool.get_enchantment_level(e));
+        fortune.max(looting)
+    });
+
+    for pool in &table.pools {
+        if !check_dynamic_condition(
+            &pool.condition,
+            has_silk_touch,
+            has_shears,
+            fortune_level,
+            params,
+            &mut rng,
+        ) {
+            continue;
+        }
+
+        let eligible_entries: Vec<&DynamicLootEntry> = pool
+            .entries
+            .iter()
+            .filter(|e| {
+                check_dynamic_condition(
+                    &e.condition,
+                    has_silk_touch,
+                    has_shears,
+                    fortune_level,
+                    params,
+                    &mut rng,
+                )
+            })
+            .collect();
+
+        if eligible_entries.is_empty() && pool.empty_weight == 0 {
+            continue;
+        }
+
+        let range = pool.max_rolls - pool.min_rolls;
+        let rolls = pool.min_rolls
+            + if range > 0 {
+                rng.next_bounded_i32(range + 1)
+            } else {
+                0
+            };
+
+        roll_dynamic_entries(
+            rolls,
+            pool.empty_weight,
+            &eligible_entries,
+            fortune_level,
+            &mut rng,
+            &mut items_to_place,
+        );
+    }
+
+    items_to_place
+}
+
+fn roll_dynamic_entries(
+    rolls: i32,
+    empty_weight: i32,
+    eligible_entries: &[&DynamicLootEntry],
+    fortune_level: i32,
+    rng: &mut Xoroshiro,
+    items_to_place: &mut Vec<ItemStack>,
+) {
+    for _ in 0..rolls {
+        let entry_weight: i32 = eligible_entries.iter().map(|e| e.weight).sum();
+        let total_weight = entry_weight + empty_weight;
+        if total_weight == 0 {
+            continue;
+        }
+
+        let mut pick = rng.next_bounded_i32(total_weight);
+        pick -= empty_weight;
+        if pick < 0 {
+            continue;
+        }
+
+        for entry in eligible_entries {
+            pick -= entry.weight;
+            if pick < 0 {
+                let count_range = entry.max_count - entry.min_count;
+                let base_count = entry.min_count
+                    + if count_range > 0 {
+                        rng.next_bounded_i32(count_range + 1)
+                    } else {
+                        0
+                    };
+
+                let mut final_count = base_count;
+                if let Some(bonus) = entry.bonus_formula {
+                    final_count = apply_bonus_formula(final_count, bonus, fortune_level, rng);
+                }
+
+                if final_count > 0 {
+                    let item_key = entry.item.strip_prefix("minecraft:").unwrap_or(&entry.item);
+                    if let Some(item) = Item::from_registry_key(item_key) {
+                        items_to_place.push(ItemStack::new(final_count as u8, item));
+                    }
+                }
+                break;
+            }
+        }
+    }
+}
+
+/// A handle to either a compile-time static loot table or a datapack dynamic loot table.
+#[derive(Clone, Debug)]
+pub enum LootTableHandle {
+    Static(&'static LootTable),
+    Dynamic(std::sync::Arc<DynamicLootTable>),
+}
+
+impl From<&'static LootTable> for LootTableHandle {
+    fn from(t: &'static LootTable) -> Self {
+        Self::Static(t)
+    }
+}
+
+impl From<std::sync::Arc<DynamicLootTable>> for LootTableHandle {
+    fn from(t: std::sync::Arc<DynamicLootTable>) -> Self {
+        Self::Dynamic(t)
+    }
+}
+
+impl LootTableHandle {
+    #[must_use]
+    pub fn generate_loot(&self, seed: i64) -> Vec<ItemStack> {
+        self.generate_loot_with_context(seed, &LootContextParameters::default())
+    }
+
+    #[must_use]
+    pub fn generate_loot_with_context(
+        &self,
+        seed: i64,
+        params: &LootContextParameters,
+    ) -> Vec<ItemStack> {
+        generate_loot_from_handle(self, seed, params)
+    }
+}
+
+#[must_use]
+pub fn get_loot_table(key: &str) -> Option<LootTableHandle> {
+    let full_key = if key.contains(':') {
+        key.to_string()
+    } else {
+        format!("minecraft:{key}")
+    };
+    pumpkin_data::loot_table::get_loot_table(key)
+        .or_else(|| pumpkin_data::loot_table::get_loot_table(&full_key))
+        .map(LootTableHandle::Static)
+}
+
+#[must_use]
+pub fn generate_loot_from_handle(
+    handle: &LootTableHandle,
+    seed: i64,
+    params: &LootContextParameters,
+) -> Vec<ItemStack> {
+    match handle {
+        LootTableHandle::Static(table) => generate_loot_with_context(table, seed, params),
+        LootTableHandle::Dynamic(table) => generate_dynamic_loot_with_context(table, seed, params),
+    }
+}
+
+fn place_items_in_chest(
     inventory: &std::sync::Arc<dyn pumpkin_inventory::Inventory>,
-    table: &LootTable,
+    mut items_to_place: Vec<ItemStack>,
     seed: i64,
 ) {
-    let mut items_to_place = generate_loot(table, seed);
-
     if items_to_place.is_empty() {
         return;
     }
@@ -266,6 +531,24 @@ pub fn fill_chest_inventory(
     }
 }
 
+pub fn fill_chest_inventory_handle(
+    inventory: &std::sync::Arc<dyn pumpkin_inventory::Inventory>,
+    handle: &LootTableHandle,
+    seed: i64,
+) {
+    let items_to_place = generate_loot_from_handle(handle, seed, &LootContextParameters::default());
+    place_items_in_chest(inventory, items_to_place, seed);
+}
+
+pub fn fill_chest_inventory(
+    inventory: &std::sync::Arc<dyn pumpkin_inventory::Inventory>,
+    table: &LootTable,
+    seed: i64,
+) {
+    let items_to_place = generate_loot(table, seed);
+    place_items_in_chest(inventory, items_to_place, seed);
+}
+
 fn shuffle_and_split_items(
     result: &mut Vec<ItemStack>,
     available_slots: usize,

crates/pumpkin/src/world/mod.rs

@@ -7279,6 +7279,23 @@ impl World {
         }
     }
 
+    #[must_use]
+    pub fn get_loot_table(&self, key: &str) -> Option<crate::world::loot::LootTableHandle> {
+        self.server.upgrade().map_or_else(
+            || {
+                let full_key = if key.contains(':') {
+                    key.to_string()
+                } else {
+                    format!("minecraft:{key}")
+                };
+                pumpkin_data::loot_table::get_loot_table(key)
+                    .or_else(|| pumpkin_data::loot_table::get_loot_table(&full_key))
+                    .map(crate::world::loot::LootTableHandle::Static)
+            },
+            |server| server.datapack_manager.get_loot_table(key),
+        )
+    }
+
     pub fn generate_loot(&self, loot_table: String) {
         let mut loot_event =
             crate::plugin::api::events::world::loot_generate::LootGenerateEvent::new(loot_table);