---
title: "Blackjack: API"
package: "@phaser-ae/blackjack"
tier: Pro
version: 3.0.0-2
released: 2026-10-14
updated: 2026-10-19
description: "Player-versus-dealer blackjack rounds from a seeded shoe, with a hidden hole card, configurable house rules, splits, doubles, insurance and surrender, and exact play-chip settlement."
url: https://phaser.io/packs/blackjack/api
site: Phaser - https://phaser.io
---

# Blackjack: API

`@phaser-ae/blackjack` — Quick seeded Blackjack with hidden cards, configurable house rules, split/double/insurance/surrender and exact play-money settlement.

## The pack

### `blackjack`

```ts
function blackjack(): Pack<{ blackjack: typeof rules }>
```

Install headless Blackjack rules; compose cards for deck operations and presentation.

## Helpers

### `blackjackHint`

```ts
function blackjackHint(view: BlackjackObservation): { action: BlackjackAction | null; reason: string; method: 'visible-heuristic' }
```

Basic-strategy-style advice using only the player hand and dealer upcard. Named rules vary; this is a heuristic.

### `blackjackTotal`

```ts
function blackjackTotal(cards: readonly Pick<Card, 'rank'>[], split = false): BlackjackTotal
```

Compute ace-adjusted Blackjack totals without reading any private game state.

### `createBlackjack`

```ts
function createBlackjack(options: BlackjackOptions = {}): BlackjackGame
```

Create a quick seeded Blackjack session.

## Classes

### `BlackjackGame`

```ts
class BlackjackGame
```

A single player against a deterministic dealer, with explicit house rules and atomic commands. The session is a
kernel history: its state is a function of the seed and the accepted commands, so a save is those commands and a
restore replays them.

- `constructor(options: BlackjackOptions = {})`
- `observation(): BlackjackObservation` — Read-only player view; use this for hints and computer play.
- `legalActions(): BlackjackAction['kind'][]` — Available verbs. Use preview for a specific bet amount.
- `preview(action: BlackjackAction): { ok: true } | { ok: false; reason: string }` — Explain legality without mutating state or consuming randomness.
- `apply(action: BlackjackAction): BlackjackResult` — Apply one command atomically. The dealer completes its rule-defined turn automatically.
- `snapshot(): BlackjackSnapshot` — Serializable, bounded command replay; never expose this privileged seed to advice code.
- `restore(snapshot: BlackjackSnapshot): void` — Reconstruct every accepted action instead of trusting edited balances, cards or phase fields.
- `hint(): ReturnType<typeof blackjackHint>` — Visible-information heuristic; no claim of perfect play or guaranteed wins.

## Types

### `BlackjackAction`

```ts
type BlackjackAction = { kind: 'bet'; amount: number } | { kind: 'hit' | 'stand' | 'double' | 'split' | 'surrender' | 'insure' | 'decline-insurance' }
```

Named round actions. Bets use even integer chips so 3:2 and half-bets stay exact.

### `BlackjackEvent`

```ts
type BlackjackEvent = { kind: 'deal'; owner: 'dealer' | 'player'; hand: number; card: Card | null } | { kind: 'reveal'; card: Card } | { kind: 'action'; action: BlackjackAction['kind']; hand: number } | { kind: 'settled'; bankroll: number }
```

Public event stream, with no unrevealed card values.

### `BlackjackHand`

```ts
interface BlackjackHand
```

A publicly visible player hand.

- `cards: Card[]` — Cards owned by this hand.
- `bet: number` — Wager already debited from the bankroll.
- `split: boolean` — Split-origin hands never receive natural payouts.
- `splitAces: boolean` — Whether split aces are locked to one extra card.
- `status: 'playing' | 'stood' | 'bust' | 'surrendered'` — Action state.
- `outcome: '' | 'win' | 'loss' | 'push' | 'blackjack' | 'surrender'` — Final outcome, empty until settlement.
- `paid: number` — Total chips returned at settlement, including the wager.

### `BlackjackObservation`

```ts
interface BlackjackObservation
```

The complete player/bot view: hidden hole cards are null, and shoe order/seed are absent.

- `phase: 'betting' | 'insurance' | 'player' | 'settled'` — Current round phase.
- `bankroll: number` — Available chips.
- `dealer: (Card | null)[]` — Dealer cards with an unrevealed hole represented by null.
- `hands: BlackjackHand[]` — Player hands.
- `active: number` — Current hand index.
- `round: number` — Number of started rounds.
- `shoeRemaining: number` — Undealt cards; no identities or order.
- `discardCount: number` — Previously discarded cards, for conservation diagnostics.
- `insuranceBet: number` — Insurance wager already debited.
- `insurancePaid: number` — Insurance chips returned.
- `rules: Omit<Required<BlackjackOptions>, 'seed'>` — Applied house rules, excluding hidden seed.
- `legal: BlackjackAction['kind'][]` — Non-bet actions currently legal.

### `BlackjackOptions`

```ts
interface BlackjackOptions
```

Supported US hole-card/peek rules. All chips are play money.

- `seed?: number` — Unsigned 32-bit seed.
- `decks?: number` — One to eight standard decks; default six.
- `bankroll?: number` — Starting chips; default 200.
- `hitSoft17?: boolean` — Hit soft 17 rather than stand; default false.
- `doubleAfterSplit?: boolean` — Permit doubling a split hand; default true.
- `maxHands?: number` — Two to four simultaneous hands; default four.
- `insurance?: boolean` — Offer half-bet insurance against an ace; default true.
- `surrender?: boolean` — Permit late surrender on the original two-card hand; default false.

### `BlackjackResult`

```ts
type BlackjackResult = { ok: true; events: BlackjackEvent[] } | { ok: false; reason: string }
```

Transactional action result.

### `BlackjackSnapshot`

```ts
interface BlackjackSnapshot
```

Replay/save format; privileged because its seed can reconstruct the shoe.

- `version: 1` — Format version.
- `options: Required<BlackjackOptions>` — Original session settings.
- `actions: BlackjackAction[]` — Accepted commands from session start.

### `BlackjackTotal`

```ts
interface BlackjackTotal
```

Ace-aware totals. A natural requires an original, unsplit two-card hand.

- `total: number` — Highest legal total, or the minimum bust total.
- `soft: boolean` — An ace still counts as eleven.
- `bust: boolean` — Total exceeds 21.
- `natural: boolean` — Two-card 21, optionally suppressed for split hands.

---

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