# FeatureTrigger

> Kinbarrow modding reference — content tree `4a103dcdb658a75a`, version `0.2.0+main.e011511f4`.

[Effects and mechanisms](https://kinbarrow.com/modding/latest/mechanisms.md)

Used by [ClassDef](https://kinbarrow.com/modding/latest/class-def.md#feature-trigger), [Npc](https://kinbarrow.com/modding/latest/npc.md#feature-trigger), [FeatDef](https://kinbarrow.com/modding/latest/feat-def.md#feature-trigger), [RaceDef](https://kinbarrow.com/modding/latest/race-def.md#feature-trigger), [SubclassDef](https://kinbarrow.com/modding/latest/subclass-def.md#feature-trigger).

This is a nested shape inside a content file. The catalog explains context validation and links real RON examples.

One data-authored class-feature trigger.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `at` | `FeatureTriggerBoundary` | required | The one typed combat boundary which raises this row. |
| `economy` | `FeatureActionEconomy` | optional | Optional turn resource paid when the trigger is accepted. At TurnStart, Some(Free) offers an activation or decline before ordinary turn effects. |
| `effects` | `Effect[]` | required | Ordered consequences from the shared `Effect` vocabulary. Validation accepts only effects with a feature-trigger reader. |
| `ledger` | `FeatureActionLedger` | optional | Optional existing ledger charged by the trigger. A paid TurnStart activation names Pool; its effects carry the cost in that pool. |
| `when` | `FeatureTriggerCondition[]` | default `[]` | Every condition must hold. Empty means the boundary alone is enough. |


## Supporting shapes

- [Effect](https://kinbarrow.com/modding/latest/mechanisms/spell/effect.md)
- [FeatureActionEconomy](https://kinbarrow.com/modding/latest/spell.md#feature-action-economy)
- [FeatureActionLedger](https://kinbarrow.com/modding/latest/spell.md#feature-action-ledger)
- [FeatureTriggerBoundary](https://kinbarrow.com/modding/latest/class-def.md#feature-trigger-boundary)
- [FeatureTriggerCondition](https://kinbarrow.com/modding/latest/class-def.md#feature-trigger-condition)