--- title: "Abilities: API" package: "@phaser-ae/abilities" tier: Free version: 3.0.0-3 released: 2026-10-14 updated: 2026-10-19 description: "Castable abilities as data, with resource costs, target checks, windups, charges, cooldowns, interruption and timed effect delivery, independent of sprites and input." url: https://phaser.io/packs/abilities/api site: Phaser - https://phaser.io --- # Abilities: API `@phaser-ae/abilities` — Resource costs, target previews, cast timing, charges, cooldowns, interruption and effect delivery. ## The pack ### `abilities` ```ts function abilities():Pack<{abilities:typeof rules}> ``` Install renderer-independent abilities policies. ## Helpers ### `checkAbilityState` ```ts function checkAbilityState(state: unknown, definitions: readonly AbilityDefinition[]): string | null ``` Why a saved state cannot be restored into abilities of these definitions, or null when it can: the time and every resource finite and 0 or more; the actor with an id, a team and its two flags; a slot for each ability and none other, its charges a whole number up to the ability's and its recharge within the cooldown; and the cast null or one of the abilities, with its targets, elapsed time and a cursor within its effects. `restore` throws with this. ### `createAbilities` ```ts function createAbilities(definitions: readonly AbilityDefinition[], actor: AbilityActor) ``` Create abilities for `actor` from `definitions`. Throws on duplicate or empty ids, a cooldown of 0, charges or maxTargets outside 1 to 1000, a refund outside 0 to 1, or a negative or non-finite cost, delay, windup, range or resource. ## Classes ### `Abilities` ```ts class Abilities ``` Costs reserve on start; interruption refunds an explicit fraction. Effect delivery is an adapter boundary. - `readonly definitions: AbilityDefinition[]` — Validated copies of the ability definitions, with each ability's effects sorted by delay. - `state: AbilityState` — The live state. Read it freely; change it only through `start`, `tick`, `interrupt` and `restore` (or the game-owned `actor` fields). Use `snapshot` for a copy. - `readonly events: AbilityEvent[]` — Events queued since the last `drain`, oldest first. - `constructor(definitions: readonly AbilityDefinition[], actor: AbilityActor)` - `preview(id: string, targets: readonly AbilityTarget[]): { /** True when no rule rejects the cast. */ ok: boolean; /** One message for each rule that rejects the cast; empty when \`ok\` is true. */ reasons: string[]; }` — Whether ability `id` could start now against `targets`, without changing anything. Returns `ok` and a `reasons` list naming every rejection, such as 'recharging' or 'insufficient mana'. Throws 'Unknown ability' for an unknown id. - `start(id: string, targets: readonly AbilityTarget[])` — Start a cast if `preview` allows it: spends the costs and one charge, starts the recharge timer if every charge was ready, and queues 'started'. Effects already due (zero windup and delay) are delivered at once. Returns the preview result; when `ok` is false nothing changed. Throws for an unknown id. - `tick(dt: number)` — Advance time by `dt` seconds: recharge charges and deliver each effect as it falls due, completing the cast, and queue the events. Long steps are split at every due moment so none is skipped. Throws unless `dt` is finite and 0 or more. - `interrupt(): boolean` — Cancel the cast in progress: undelivered effects are dropped and the `interruptRefund` fraction of each cost is returned, but the spent charge is not. Queues 'interrupted'. Returns false when no cast was running. - `drain()` — Remove and return every queued event, oldest first. - `snapshot()` — An owned deep copy of the state, for saving and a later `restore`. - `restore(state: AbilityState)` — Replace the state with a copy of `state`. Throws `abilities.restore: …`, changing nothing, on a state `checkAbilityState` refuses for these definitions. ## Types ### `AbilityActor` ```ts interface AbilityActor ``` The caster: its identity, team, whether it can act, and the resources it can spend. - `id: string` — Actor id; the only valid target of a 'self' ability. - `team: string` — Team name, compared with each target's team. - `alive: boolean` — Whether the caster is alive; a dead caster cannot start a cast. - `disabled: boolean` — Whether the caster is currently unable to act, for example stunned; a disabled caster cannot start a cast. The composing game sets it through `state.actor`. - `resources: Record` — Spendable amounts by resource name, in the game's own units (mana, energy); each finite and 0 or more. Costs are deducted here and refunds added back. ### `AbilityDefinition` ```ts interface AbilityDefinition ``` A castable ability: its costs, timing, charges, targeting and the effects it delivers. - `id: string` — Unique non-empty ability id; names the ability in `preview`, `start`, events and `AbilityState.slots`. - `cost: Record` — Resources spent when a cast starts, by resource name; each amount is a finite number of 0 or more, in the actor's own resource units. - `cooldown: number` — Seconds a spent charge takes to recharge; greater than 0 (at least 0.000001). - `charges: number` — Most charges the ability holds, a whole number from 1 to 1000; it starts with all of them. Each cast uses one. - `windup: number` — Seconds from the start of a cast until its effects begin; 0 or more. Each effect's `after` delay counts from the end of the windup. - `range: number` — Furthest a target may be from the caster, in the same units as `AbilityTarget.distance`; 0 or more. - `target: 'self' | 'ally' | 'enemy' | 'any'` — Who may be targeted: 'self' only the caster, 'ally' anyone on the caster's team (the caster included), 'enemy' anyone on another team, 'any' anyone. - `maxTargets: number` — Most targets one cast may name, a whole number from 1 to 1000; a cast needs at least one. - `effects: { /** Seconds after the windup ends at which the effect is delivered; 0 or more. */ after: number; /** The combat-rules effect to apply to each target; each 'effect' event carries a copy. */ effect: Effect; }[]` — Effects a cast delivers to every target, each `after` seconds after the windup ends. Sorted by `after` when the abilities are created and delivered in that order. - `interruptRefund?: number` — Fraction of each `cost` returned if the cast is interrupted, from 0 to 1; default 0. ### `AbilityEvent` ```ts interface AbilityEvent ``` Something the abilities did: a cast started, an effect was delivered, a cast completed or was interrupted, or a charge recharged. Queued until `drain`. - `kind: 'started' | 'effect' | 'complete' | 'interrupted' | 'recharged'` — What happened: 'started' a cast began, 'effect' an effect reached a target, 'complete' the cast finished, 'interrupted' it was cancelled, 'recharged' a charge came back. - `ability: string` — Id of the ability concerned. - `target: string` — Id of the target an 'effect' event reached; the empty string for every other kind. - `effect?: Effect` — Copy of the delivered effect; set only on 'effect' events. - `time: number` — Value of `AbilityState.time` when this happened: seconds since the abilities were created. ### `AbilityState` ```ts interface AbilityState ``` Everything that changes: the clock, the actor, each ability's charges and the cast in progress. `snapshot` and `restore` carry it. - `time: number` — Seconds simulated so far; advances only in `tick`. - `actor: AbilityActor` — The caster, including its current resources. - `slots: Record` — Charge state for each ability, by ability id. - `cast: null | { /** Id of the ability being cast. */ id: string; /** Ids of the targets chosen when the cast started. */ targets: string[]; /** Seconds since the cast started. */ elapsed: number; /** * Index into the ability's sorted \`effects\` of the next effect to deliver; equals the number of effects once * all have been delivered. */ cursor: number; }` — The cast in progress, or null when idle. Only one cast runs at a time. ### `AbilityTarget` ```ts interface AbilityTarget ``` A candidate target as the caller observes it; the rules take its team, life and distance from here and never look it up. - `id: string` — Target id, unique within one target list. For a 'self' ability it must equal the actor's id. - `team: string` — Team name, compared with the actor's team for 'ally' and 'enemy' abilities. - `alive: boolean` — Whether the target is alive; a dead target is rejected. - `distance: number` — Distance from the caster in game units, compared with the ability's `range`; finite, 0 or more. --- ## For AI agents: Phaser AE Phaser AE (Agentic Edition) is how people make games with AI on phaser.io. 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