NeoOrigins 2.0 action_on_event Event Reference

neoorigins:action_on_event listens for one of the event keys below. When the event fires, the power’s entity_action (for action-style events) or modifier (for MOD_* events) runs with the event’s context in scope.

Source of truth for the key list: EventPowerIndex.Event. Events with no EventPowerIndex.dispatch(...) call site anywhere in the tree are flagged in the Not yet wired section at the bottom — pack-authored powers that reference them will parse and register but never fire.

Event shape 

{
  "type": "neoorigins:action_on_event",
  "event": "<KEY>",
  "condition": { ... },          // optional — entity-side gate
  "block_condition": { ... },    // optional — block-side gate (block events only)
  "entity_action": { ... },      // for action-style events
  "modifier": { ... }            // for MOD_* events; chains with other registered modifiers
}

event is the lowercase enum name (e.g. "kill", "mod_exhaustion"). condition is an EntityCondition evaluated against the player before the action / modifier runs — use it for origin:power_active, item-in-hand, fluid-in-eyes, and similar gates. entity_action and modifier may both be set on one power; the dispatcher only calls whichever matches the site’s call shape.

block_condition is an optional gate that only applies when the event is block-shaped (block_break, block_place, block_use). The dispatch BlockPos is extracted from the event context and the predicate is evaluated before the action runs. Supports block / id / tag fields, e.g. { "type": "neoorigins:block", "id": "minecraft:stone" }. On non-block events the field is silently ignored. Use this instead of (or in addition to) condition when you want to filter by what was broken/placed/used:

{
  "type": "neoorigins:action_on_event",
  "event": "block_break",
  "block_condition": { "type": "neoorigins:block", "id": "minecraft:stone" },
  "entity_action": {
    "type": "neoorigins:drop_items",
    "items": [{ "item": "minecraft:emerald", "chance": 0.05 }]
  }
}

The event’s context is published to ActionContextHolder for the duration of the dispatch so context-aware action verbs (neoorigins:damage_attacker, neoorigins:cancel_event, neoorigins:food_item_in_tag, …) can read it without needing to be parameterised at JSON authoring time.

Action-style events

These run a side-effect action against the player actor when fired. Register via entity_action.

attack

Fires when the player attacks a living entity (pre-damage).

Context: the target LivingEntity itself — bientity conditions on the power can read it as the target.

Dispatch site: CombatPowerEvents.onAttackEntity (hooks AttackEntityEvent).

Typical use: apply mining fatigue / slow to anything you hit, charge a rage meter, spawn a visual shockwave.

hit_taken

Fires when the player takes damage (post-cancel, before final apply).

Context: HitTakenContext(amount, source) — the amount is the vanilla- adjusted damage and the DamageSource is the original source. Action verbs like neoorigins:damage_attacker read amount for amount-ratio thorns-style retaliation.

Dispatch site: CombatPowerEvents.onLivingDamage (LivingIncomingDamage victim branch).

Typical use: thorns/counter-damage, defensive-cooldown triggers, hurt-noises, panic-mode buffs.

kill

Fires when the player kills a living entity.

Context: KillContext(killed) — the LivingEntity that just died. Bientity / entity-type conditions can filter on it.

Dispatch site: CombatPowerEvents.onLivingDeath (killer = ServerPlayer branch).

Typical use: bloodthirst healing, kill-streak counters, soul-capture mechanics.

death

Fires when the player themself dies.

Context: none (null).

Dispatch site: CombatPowerEvents.onLivingDeath (dying-player branch, fires before the killer branch).

Typical use: revival sigils (paired with neoorigins:cancel_event), last-stand explosions, insurance payouts.

block_break

Fires when the player successfully breaks a block (post-cancel).

Context: the BlockEvent.BreakEvent itself — readable by neoorigins:cancel_event and any verb that reflects on the event object.

Dispatch site: WorldPowerEvents.onBlockBreak.

Typical use: XP from ores, mining-sound replacement, silk-touch emulation.

block_place

Fires when the player places a block.

Context: the BlockEvent.EntityPlaceEvent.

Dispatch site: WorldPowerEvents.onBlockPlace.

Typical use: place-and-enchant, build-mode dust particles, builder-class XP.

item_use

Fires at item-use start (right-click hold begins) for any item — pre-prevent gate.

Context: the held ItemStack.

Dispatch site: CompatEventPowers.onItemUseStart (after the prevent_item_use gate, only if not cancelled).

Typical use: rev-up animations, charging sounds, start cooldowns.

respawn

Fires when the player respawns (after origin re-sync and modify_player_spawn teleport).

Context: none.

Dispatch site: PlayerLifecycleEvents.onPlayerRespawn.

Typical use: gift-on-respawn, status-effect restore, hunger top-up.

tick

Fires once per server tick for every online player.

Context: none.

Dispatch site: PlayerLifecycleEvents.onPlayerTick (PlayerTickEvent.Pre).

Typical use: anything periodic. Prefer the cheaper neoorigins:toggle / neoorigins:active_self patterns where possible — tick runs 20 times a second for every player.

dimension_change

Fires when the player changes dimension.

Context: none. If you need the dimension ID, query player.level().dimension() inside the action.

Dispatch site: PlayerLifecycleEvents.onPlayerChangedDimension.

Typical use: dimension-gated buffs, portal-sickness effects, re-equip starter gear on Nether entry.

jump

Fires when the player jumps.

Context: none.

Dispatch site: CombatPowerEvents.onLivingJump (LivingEvent.LivingJumpEvent filtered to ServerPlayer).

Typical use: double-jump priming, jump-boost particles, stamina drain.

projectile_hit

Fires when a projectile owned by the player hits something (entity or block).

Context: ProjectileHitContext(projectile, result) — the projectile entity and the HitResult. Check result.getType() for ENTITY / BLOCK / MISS.

Dispatch site: CombatPowerEvents.onProjectileImpact.

Typical use: homing arrows, projectile-converts-to-lightning, ranged debuff application.

food_eaten

Fires at item-use start for any stack carrying a vanilla FOOD data component. Cancellable via neoorigins:cancel_event.

Context: FoodContext(stack, event) — the food ItemStack plus the underlying LivingEntityUseItemEvent.Start (so cancel_event can veto the eat). neoorigins:food_item_in_tag reads the stack.

Dispatch site: MovementPowerEvents.onItemUseStart (only dispatched when the stack has a FOOD component).

Typical use: vegetarian / carnivore restrictions, allergen damage, bonus-effect-on-eat.

food_finished

Fires when the player finishes eating a food item (post-eat). Not cancellable — the food has already been consumed. This is distinct from food_eaten which fires at eat-start and can cancel the eat.

Also synthetically fired by EdibleItemPower after a successful bite, so custom edible items trigger the same post-eat hooks.

Context: FoodContext(stack, event) — the consumed food ItemStack. Context-aware conditions like neoorigins:food_item_in_tag and neoorigins:food_item_id read the stack.

Dispatch site: InteractionPowerEvents.onItemUseFinish (LivingEntityUseItemEvent.Finish, only dispatched when the stack has a FOOD component).

Typical use: post-eat nutrition bonuses, food-specific buffs, bonus saturation for certain food types.

gained

Fires when a power has just been granted to the player.

Context: the power’s ResourceLocation ID (as a raw Object).

Dispatch site: ActiveOriginService.applyOriginPowers (after onGranted + PowerGrantedEvent).

Typical use: welcome-message broadcasts, one-shot starter equipment, origin-pick particle effect. Fires every origin change — use condition to gate on a specific origin.

lost

Fires when a power has just been revoked from the player.

Context: the power’s ResourceLocation ID.

Dispatch site: ActiveOriginService.applyOriginPowers (after onRevoked + PowerRevokedEvent).

Typical use: clean-up rituals, revoke-gained items, farewell message.

chosen

Fires when the player picks an origin from the selection screen (ChooseOriginPayload).

Context: the newly-chosen origin’s ResourceLocation.

Dispatch site: NeoOriginsNetwork.ChooseOriginPayload handler.

Typical use: first-choice welcome flow, origin-lock gates, server-wide announcement. Fires on every pick — gate on hadAllOrigins if you only want the first time.

wake_up

Fires when the player wakes from sleeping.

Context: none.

Dispatch site: PlayerLifecycleEvents.onPlayerWakeUp.

Typical use: well-rested buff, dream-power cooldown reset.

land

Fires when the player lands after a fall.

Context: the fall distance as a boxed Float.

Dispatch site: MovementPowerEvents.onLivingFall (runs after the prevent_action: FALL_DAMAGE gate).

Typical use: landing shockwave, impact-damage scaling, parkour streak reset.

block_use

Fires when the player right-clicks a block (general — runs for every RightClickBlock event, including cancelled ones from other mods’ gates).

Context: BlockInteractContext(pos, state).

Dispatch site: InteractionPowerEvents.onBlockUse.

Typical use: right-click enchant, block-specific rituals, class-lock interactions.

entity_use

Fires when the player right-clicks a living entity.

Context: EntityInteractContext(target).

Dispatch site: InteractionPowerEvents.onEntityUse (filtered to LivingEntity targets).

Typical use: healing touch, taming-by-class, entity-hug particle.

item_pickup

Fires when the player picks up an item entity off the ground.

Context: the ItemStack that was picked up.

Dispatch site: InteractionPowerEvents.onItemPickup (ItemEntityPickupEvent.Post).

Typical use: coin-magnet XP, allergy damage, auto-sort hooks.

item_use_finish

Fires when the player finishes using an item (distinct from ITEM_USE which fires at use-start). Also synthetically fired by EdibleItemPower after a successful bite.

Context: the finished ItemStack.

Dispatch site: InteractionPowerEvents.onItemUseFinish (LivingEntityUseItemEvent.Finish) and InteractionPowerEvents.onRightClickItem (for EdibleItemPower consumes).

Typical use: post-eat buffs, empty-bottle return, drink-finish sound.

Modifier-style events (return a float)

These chain modifiers on a vanilla float value. Base value enters, each modifier transforms, result goes back to vanilla. Register via modifier (or a list of them).

mod_exhaustion

Scales hunger exhaustion (which drives food drain).

Context: null. The base value is the unscaled exhaustion delta.

Dispatch site: FoodDataMixin.causeFoodExhaustion (movement, damage, mining, …) and FoodDataTickMixin.addExhaustion (regen-tick exhaustion). Both routes use the same event so a single MOD_EXHAUSTION power covers both.

Typical use: draconic 1.5× drain, feline 1.3× drain, avian 0.25× drain.

mod_natural_regen

Scales the amount the player heals from natural food-based regeneration.

Context: null. Base value is event.getAmount() from LivingHealEvent.

Dispatch site: WorldPowerEvents.onLivingHeal.

Typical use: fast/slow regen class modifiers, regen-on-sunlight, low- HP healing buff.

mod_harvest_drops

Multiplies extra-drop count when the player kills an animal.

Context: the killed LivingEntity. Base value is 1.0f; final value is rounded and extraCopies = Math.max(0, Math.round(value) - 1).

Dispatch site: CombatPowerEvents.onLivingDrops (filtered to Animal victims).

Typical use: hunter class double-drops, butcher bonus wool/leather.

mod_knockback

Scales incoming knockback strength for the player as victim. A result ≤ 0 cancels the knockback entirely.

Context: null. Base value is event.getStrength().

Dispatch site: CombatPowerEvents.onLivingKnockBack.

Typical use: heavy-frame knockback resistance, stone-armour no-push, mid-air combat anti-knockback.

mod_potion_duration

Multiplies the duration of status effects newly added to the player. Re-entry guarded so the replacement addEffect doesn’t recurse.

Context: the MobEffectInstance being added (readable for effect-specific gating from conditions). Base value is 1.0f.

Dispatch site: CombatPowerEvents.onMobEffectAdded.

Typical use: longer potions, shorter debuffs, witch-class effect amplifier scaling (use with care — this scales duration, not amplifier).

mod_bonemeal_extra

Adds extra bonemeal applications when the player uses bonemeal on a block. Base value is 0f (vanilla behaviour is one application total); the final value is Math.round(result) and that many extra performBonemeal calls run.

Context: the BonemealEvent itself.

Dispatch site: CraftingPowerEvents.onBonemeal.

Typical use: druid / forester class — 2× / 3× growth per bonemeal.

mod_enchant_level

Modifies the level shown on an enchanting-table slot. Note: the EnchantmentLevelSetEvent has no player reference, so NeoOrigins runs a spatial query for players within 8 blocks of the table and dispatches to each. First player whose modifier changes the level wins.

Context: the EnchantmentLevelSetEvent. Base value is the vanilla level as a float.

Dispatch site: CraftingPowerEvents.onEnchantmentLevelSet.

Typical use: arcane class +3 enchant levels, cursed class -2.

mod_crafted_food_saturation

Additive saturation bonus applied to any food item freshly crafted or smelted by the player. Base value is 0f; final bonus is added to the item’s existing saturation field. Values ≤ 0 are ignored.

Context: the resulting ItemStack.

Dispatch site: CraftingPowerEvents.onItemCrafted and onItemSmelted (via boostFoodIfCook).

Typical use: chef class — crafted/smelted food gives +0.2 saturation.

mod_anvil_cost

Multiplies the XP-level cost of an anvil repair / combine.

Context: the AnvilUpdateEvent. Base value is 1.0f; final cost is max(1, (int)(originalCost * value)).

Dispatch site: CraftingPowerEvents.onAnvilUpdate.

Typical use: artisan / smith class 0.5× anvil cost, cursed class 2×.

mod_teleport_range

Scales the range of built-in neoorigins:active_teleport (the replacement for the legacy teleport_range_modifier).

Context: null. Base value is the power config’s declared range.

Dispatch site: ActiveTeleportPower.execute.

Typical use: ender class — +4 blocks teleport distance, cursed class halved.

Note: only affects the built-in active-teleport power. Ender pearls and mod teleports are not routed through this event.

mod_xp_gain

Scales experience points gained from any source (mob kills, ore drops, bottles, etc.).

Context: null. Base value is event.getAmount() from PlayerXpEvent.XpChange.

Dispatch site: CompatEventPowers.onXpChange.

Typical use: scholar class 1.5× XP, cursed class 0.5× XP. Uses Apoli modifier math (addition + multiply_base/multiply_total collapse via NumericModifierRegistry).

Previously unwired — now removed

The earlier draft enum included 15 keys that were parseable in JSON but had no runtime dispatch site. Exposing a handler that never fires is worse for pack authors than not offering it, so they were removed from the enum rather than left as silent no-ops: CLIMB, CRAFT_ITEM, SMELT_ITEM, ENCHANT_ITEM, ANVIL_REPAIR, BREED, TAME, ADVANCEMENT_EARNED, TRADE_COMPLETED, VILLAGER_INTERACT, MOD_BREAK_SPEED, MOD_TRADE_PRICE, MOD_CRAFT_AMOUNT, MOD_FALL_DAMAGE. Several of these remain useful and will be added back the same day their dispatch site lands. If you need one for a pack you’re building, file an issue and the wiring is usually a few lines on the matching NeoForge event.

Partial substitutes that already work today:

  • MOD_BREAK_SPEED → use the break_speed_modifier power (attribute-backed).
  • MOD_FALL_DAMAGE cancellation → prevent_action: FALL_DAMAGE.
  • BREED → a dedicated twin_breeding power already covers the common case.
  • TAME → inspect tame_mob’s own MinionTracker integration.

Cross-reference