---
title: "Game feel: API"
package: "@phaser-ae/feel"
tier: Free
version: 3.0.0-4
released: 2026-10-14
updated: 2026-10-19
description: "Camera shake, trauma, screen flash, hit-stop, slow motion and zoom punch, the screen effects that make every impact land, in 2D and 3D."
url: https://phaser.io/packs/feel/api
site: Phaser - https://phaser.io
---

# Game feel: API

`@phaser-ae/feel` — Camera shake, trauma, screen flash, hit-stop, slow motion and zoom punch: the juice of every impact, on the render only.

## The pack

### `feel`

```ts
function feel(options: FeelOptions = {}): Pack<{ feel: FeelApi }>
```

The feel pack: `game.feel`, a simulate step after `physics-2d`, all state reset on scene exit. No world
requirement: it writes the KERNEL camera's shake and punch, which every world shares. A 2D world adds them to its
rendered offset; a 3D world jitters the look and narrows the fov. `flash` alone needs a screen-space world, and
says so. Throws on an option out of range.

## Types

### `FeelApi`

```ts
interface FeelApi
```

What `game.feel` presents. Defaults: shake 6 / 0.3 s, addTrauma 0.3, flash white / 0.25 s / alpha 1, hitstop
0.08 s, slowMotion 0.3 / 0.5 s / 0.25 s ramp, zoomPunch 0.1 / 0.25 s.

- `shake(power?: number, duration?: number, options?: ShakeOptions): void` — A jitter of up to `power` world units (pixels in a 1:1 2D game) that falls away over `duration` seconds. A new shake replaces the running one unless the running one is still stronger now, after its decay.
- `addTrauma(amount?: number): void` — Add `amount` (0 to 1) to the trauma, clamped to 1. Trauma drives its own shake, `traumaPower` × trauma^`traumaExponent`, and drains at `traumaDecay` per second, so knocks accumulate: three small hits shake harder than one, and a big one cannot be outdone by a small one. It adds to any `shake` running.
- `flash(color?: string, duration?: number, alpha?: number): void` — A full-screen colour wash fading out over `duration` s. It is one screen-space object, so it needs `world-screen` composed; without one it is a no-op and says so once in dev, because a silent flash is indistinguishable from an explosion that did not fire.
- `hitstop(seconds?: number): void` — Freeze the sim for `seconds` of wall time (timeScale 0), then restore the scale in force before. Overlapping calls take the longer remaining time.
- `slowMotion(scale?: number, seconds?: number, rampOut?: number): void` — Run the sim at `scale` (0 to 1) for `seconds` of wall time, then ease back to the scale in force before over `rampOut` seconds: a dramatic kill, a near miss. A new call replaces a running one; a hit-stop freezes on top.
- `zoomPunch(amount?: number, duration?: number): void` — Zoom in by `amount` (0.1 = 10 %) and ease back quadratically over `duration` s. A new punch replaces the current one.
- `readonly shaking: boolean` — True while a shake is running or trauma is above zero.
- `readonly trauma: number` — The current trauma, 0 to 1.

### `FeelOptions`

```ts
interface FeelOptions
```

Manifest options for the feel pack; every one is optional.

- `shakeDecay?: ShakeDecay` — Default decay curve for `shake` when its options name none; default `linear`.
- `traumaPower?: number` — Camera offset in world units (pixels in a 1:1 2D game) at full trauma, 1; default 18.
- `traumaDecay?: number` — Trauma lost per second, 0.05 to 20; default 2.5, so a full knock dies away in 0.4 s.
- `traumaExponent?: number` — The offset follows trauma raised to this power, 1 to 4; default 2, so small knocks stay small and big ones jolt.
- `traumaFrequency?: number` — New random trauma offsets per second, eased between, 0 to 120; default 0, a new offset every simulation step.
- `traumaRoll?: number` — Degrees the view turns at full trauma, following trauma^`traumaExponent` as the offset does; 0 to 30, default 0 (none). Needs `post`, as `ShakeOptions.roll` does.

### `FeelTrauma`

```ts
interface FeelTrauma
```

What `feel` registers for other packs (kind `feel`, name `trauma`), so a pack that requires `feel` can knock the camera
without the game handing it `game.feel`: `k.registry.get<FeelTrauma>('feel', 'trauma')?.add(0.4)`.

- `readonly name: 'trauma'` — Always `'trauma'`.
- `add(amount: number): void` — Add trauma, as `game.feel.addTrauma` does.

### `ShakeDecay`

```ts
type ShakeDecay = 'linear' | 'quadratic' | 'none'
```

How a shake's strength falls over its duration: `linear`, `quadratic` (eases out: strong, then a long tail), or `none` (full strength until it stops).

### `ShakeOptions`

```ts
interface ShakeOptions
```

How one `shake` moves the camera; every field is optional.

- `axis?: 'both' | 'x' | 'y'` — `both` (default) jitters x and y independently; `x` or `y` jitters along that axis only. Ignored when `angle` is set.
- `angle?: number` — Shake along one direction only, in radians (0 is +x, π/2 is +y, down the screen in 2D): a knock from a hit, a recoil. Default none, which uses `axis`.
- `decay?: ShakeDecay` — How the strength falls over the duration; default the pack's `shakeDecay` option, itself `linear` by default.
- `frequency?: number` — New random offsets per second, eased between, for a slower rumble; 0 (the default) picks a new offset every simulation step, the classic buzz. Up to 120.
- `roll?: number` — Also turn the view by up to this many degrees, jittered and decaying as the offset does: a rotational shake. It needs `post` composed, because it turns the finished world image about the screen centre (zoomed just enough to keep the corners covered) while the HUD stays still; without `post` it throws in development. Default 0.

---

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