`data/damage_hooks/`

A damage hook set: named data hooks an archetype carries, listed in its manifold-gameplay:damage-hooks component (armour by body region, a creature’s thick hide). A hook changes, cancels or answers a hit at one stage of the damage pipeline. Effects (damage_hooks) and item kinds (grants.damage_hooks) carry the same hooks inline. Loaded by the server only.


Registry	`manifold:damage-hooks`
Files	`data/damage_hooks/.ron`, `.update.ron`, `*.final.ron`
Sides	server: only the server loads it
Reads	`manifold:predicate`, `manifold:stat`
Contract	Gameplay framework, data stage

Entry

A record, written DamageHooks(..); the name before the parentheses is optional.

Field	Type	Required	Default	Description
`id`	`string`	yes		The set’s key, `<mod-id>:<name>`.
`hooks`	list of `DamageHook`	yes		The hooks.

Example

No bundled file declares one yet. From the reference’s test fixture, crates/manifold-server-state/tests/data-reference-fixture/data/damage_hooks/thick_hide.ron, which the data stage loads in its tests:

DamageHooks(
    id: "dataref-fixture:thick_hide",
    hooks: [
        DamageHook(stage: Mitigate, side: Victim,
            when: ContextTags((any: ["manifold:region.head"])), action: Multiply(value: -0.5)),
        DamageHook(stage: PostHit, side: Victim,
            action: Reflect(fraction: 0.25, damage_type: "manifold:generic")),
    ],
)

Types

`DamageHook`

A data hook on the damage pipeline, evaluated in the damage context (This is the victim; v.damage_amount is the stage’s amount). Within a stage, hooks run by priority, then side, then source, then list order.

A record: DamageHook(..) or (..).

Field	Type	Required	Default	Description
`stage`	`DamageStage`	yes		The pipeline stage it runs at, which limits its actions.
`side`	`HookSide`	yes		Which participant carries it: an `Attacker` hook on a sword’s effect runs when its holder attacks, a `Victim` hook on a shield’s when its holder is hit.
`priority`	`i16`	no	`0`	Higher runs first, -32768 to 32767.
`when`	`condition` or `None`	no	always	A condition that must hold.
`action`	`DamageAction`	yes		What it does.

`DamageStage`

A stage of the damage pipeline.

Variant	Written	Description
`Admit`	`Admit`	Before anything: `Cancel`.
`Gather`	`Gather`	The attacker’s part: `Add`, `Multiply`, `Set`, `AddContextTag`.
`Convert`	`Convert`	Between elements: `Convert`.
`Mitigate`	`Mitigate`	The victim’s part: `Add`, `Multiply`, `Set`.
`PreApply`	`PreApply`	Last changes (blocks, parries, shields): all of the above and `Cancel`.
`PreDeath`	`PreDeath`	A killing hit only: `Cancel` (the victim survives), `ApplyEffect`.
`PostHit`	`PostHit`	After the hit: `ApplyEffect`, `Reflect`, `Leech`, `Knockback`, `Cue`.
`PostKill`	`PostKill`	After a kill: as `PostHit`.

`HookSide`

The participant a hook belongs to.

Variant	Written	Description
`Attacker`	`Attacker`	The attacker.
`Direct`	`Direct`	The direct source (an arrow).
`Owner`	`Owner`	The attacker’s owner.
`Victim`	`Victim`	The victim.

`DamageAction`

What a hook does. Actions may also be written positionally, in field order (Cancel("x:cancel.blocked")); Add, Multiply and Set take (<value>) or (<element>, <value>).

Variant	Written	Description
`Add`	`Add(value: .., element: ..)`	Adds to an element’s amount.
`Multiply`	`Multiply(value: .., element: ..)`	Multiplies by `1 + value`, on one element or all of them.
`Set`	`Set(value: .., element: ..)`	Sets one element’s amount, or the total (rescaling the elements).
`Convert`	`Convert(from: .., to: .., fraction: ..)`	Moves a fraction of one element’s amount into another.
`Cancel`	`Cancel(reason: ..)`	Stops the hit, with a reason tag (`manifold:cancel.*` or the game’s).
`AddContextTag`	`AddContextTag(tag: ..)`	Adds a tag to the hit’s context tags.
`ApplyEffect`	`ApplyEffect(to: .., effect: .., level: ..)`	Applies an effect to a participant, with the hook’s holder as source.
`Reflect`	`Reflect(fraction: .., damage_type: ..)`	Thorns: deals a fraction of the applied amount back to the attacker as a new hit (never more than two levels deep).
`Leech`	`Leech(fraction: .., resource: ..)`	Lifesteal: heals the attacker by a fraction of the applied amount.
`Knockback`	`Knockback(add: ..)`	Adds to the hit’s horizontal knockback, m/s.
`Cue`	`Cue(cue: ..)`	Plays a cue at the hit.

Add fields:

Field	Type	Required	Default	Description
`value`	`number`	yes		The amount, a number.
`element`	`string` or `None`	no	the hit’s primary element	The element (`manifold:element` key).

Multiply fields:

Field	Type	Required	Default	Description
`value`	`number`	yes		The change (`-0.5` halves).
`element`	`string` or `None`	no	every element	The element.

Set fields:

Field	Type	Required	Default	Description
`value`	`number`	yes		The amount.
`element`	`string` or `None`	no	the total	The element.

Convert fields:

Field	Type	Required	Description
`from`	`string`	yes	The element taken from.
`to`	`string`	yes	The element given to.
`fraction`	`number`	yes	The fraction, clamped to 0..=1.

Cancel fields:

Field	Type	Required	Default	Description
`reason`	`string`	yes		The reason tag.

AddContextTag fields:

Field	Type	Required	Default	Description
`tag`	`string`	yes		The tag.

ApplyEffect fields:

Field	Type	Required	Default	Description
`to`	`subject`	yes		The participant.
`effect`	`string`	yes		The effect (`manifold:effect` key).
`level`	`number`	no	the holding effect’s	The effect’s level.

Reflect fields:

Field	Type	Required	Default	Description
`fraction`	`number`	yes		The fraction.
`damage_type`	`string`	yes		The reflected hit’s damage type.

Leech fields:

Field	Type	Required	Default	Description
`fraction`	`number`	yes		The fraction.
`resource`	`string`	no	`manifold:health`	The resource healed (`manifold:stat` key).

Knockback fields:

Field	Type	Required	Default	Description
`add`	`number`	yes		The speed added.

Cue fields:

Field	Type	Required	Default	Description
`cue`	`string`	yes		The cue (`manifold:cue` key).

Value forms used here: condition, number, subject.

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