---
title: "Turn battle"
package: "@phaser-ae/turn-battle"
tier: Free
version: 3.0.0-0
released: 2026-10-19
updated: 2026-10-19
description: "Classic turn-based battles as a state machine over plain data, with speed order, attacks, skills, items, defending, fleeing, an element wheel, criticals and a Break gauge."
url: https://phaser.io/packs/turn-battle
site: Phaser - https://phaser.io
---

# Turn battle

Turn-based battles as a state machine over plain data. Two sides of fighters act in speed order, every action resolves
through rules you can change, and the battle hands your screen a list of events to play at its own pace.

## What it does

You make a `Battle` from fighter definitions, each with a side, six stats (health, magic, attack, defence, speed and
luck), and optionally an element and Break shield points. `next` moves to the next fighter's turn, starting a new round
in speed order when one ends, and returns who is acting. Your screen shows a menu for a hero or a telegraph for a foe,
then calls `act` with the choice: attack, skill, item, defend, flee or wait. An action that cannot be done returns false
and keeps the turn, so a bad menu choice never skips anyone.

Every number lives in the rules. The base damage is attack less half the defence, with a spread and a minimum, and
criticals come from luck. Round the element wheel each element beats another: a weakness hit deals more and knocks a
point off the target's Break gauge, a resisted hit deals less, and when the gauge empties the fighter spends its next
turn recovering and takes extra damage meanwhile. Defending halves the damage taken and restores some magic. Difficulty
scales the foes' health and attack.

The battle draws nothing and waits for nothing. `drain` returns events in order, such as `round`, `turn`, `hit`,
`break`, `recover`, `down`, `heal`, `defend`, `flee` and `end`, and your screen plays them however it likes. Random
numbers come from the stream you pass, so the same seed and choices replay the same battle, and `snapshot` and
`restore` hold its whole state. The rules are also exported on their own (`damage`, `isCrit`, `turnOrder`,
`fleeSucceeds` and more), for a game that resolves fights its own way.

## Features

- **Speed-ordered rounds** — fighters act in speed order, with `next`, `actor`, `round` and `order` to drive a screen.
- **Six actions** — attack, skill, item, defend, flee and wait.
- **An element wheel** — weakness hits at 1.5 times and resisted hits at half by default, on fire, ice, lightning and
  earth or a wheel of your own.
- **The Break gauge** — shield points that weakness hits empty, costing the fighter a turn and leaving it open to extra
  damage.
- **Criticals** — a chance from luck, double damage by default.
- **Skill effects as a registry** — damage, heal, guard and haste built in, and effects of your own, each saying whom
  it aims at and what it does.
- **A foe policy** — `choose` decides what foes do; by default they attack a random standing opponent.
- **Menu helpers** — `targets`, `reach` and `picks` say whom an action can reach and what a menu should ask for.
- **Rules as data** — every factor and chance, from `critFactor` to `fleeChance` and `dropChance`, plus difficulty
  scaling.
- **Events, replays and snapshots** — every change reported, the same battle from the same seed, and saves mid-fight.

## Good for

- **JRPG battles**: a party against a group of monsters, with weaknesses to find and shields to break.
- **Tactics skirmishes without a grid**, where only turn order and stats matter.
- **A card duel's combat phase**, resolved turn by turn.
- **Auto-battlers**, with both sides choosing through policies.
- **Turn-based encounters inside other genres**, such as an adventure game or a dungeon crawler that cuts to a battle.

## Make it yours

`BattleOptions` takes `rng`, `rules` over `BATTLE_RULES`, `effects`, `choose` and `canFlee`. The rules cover the
`wheel`, `weakFactor` (1.5), `resistFactor` (0.5), `critFactor` (2), `critChance` (luck over 100), the `base` formula,
the `spread` (0.2), `minDamage`, `brokenFactor`, `defendFactor`, `defendMp`, `hasteFactor`, `hasteTurns`, `healAtk`,
`fleeChance` (0.6), `dropChance` (0.3) and `difficulty` (gentle, fair and cruel multipliers).

Two different uses: a classic party against wolves on the default wheel, with Break shields on the wolves and fleeing
allowed; and a battle of its own with a light-and-dark wheel, triple criticals, a skill that drains life, foes that
gang up on the weakest hero, haste that wears off and no fleeing.

## A quick look

Two fighters, a loop over turns, and the events for the screen:

```ts
import { Battle } from '@phaser-ae/turn-battle';
const b = new Battle([
  { id: 'wren', side: 'hero', stats: { hp: 40, mp: 12, atk: 12, def: 4, spd: 9, lck: 5 }, element: 'fire' },
  { id: 'wolf', side: 'foe', stats: { hp: 30, mp: 0, atk: 8, def: 3, spd: 7, lck: 2 }, element: 'ice', breaks: 2 },
], { rng: () => game.rng.next() });
for (let f = b.next(); f; f = b.next()) {
  b.act(f.side === 'hero' ? { kind: 'attack', target: 'wolf' } : b.auto());
  for (const e of b.drain()) { /* round, turn, hit, break, recover, down, heal, defend, flee, end */ }
}
b.result;   // 'win' | 'lose' | 'flee'
```

## Works with

- `rpg` — its battle screen is a view over this battle.
- `party` — heroes with levels, gear and a bag to bring into a fight.
- `rpg-world` — monsters with elements, shields and drops, written as data.
- `combat-rules` — real-time damage with flat armour, resistances, shields and timed statuses instead; the two do not
  share a damage model.
- `abilities` — cooldowns and cast times for real-time combat.

## Good to know

- Two sides and no positions: there are no rows, ranges or areas, and a skill that hits all hits a whole side.
- One action a turn, with no reactions, counters or interrupts.
- No timed statuses beyond defending and haste; a game's own statuses live in its fighters' `data` and its skill
  effects.
- An item's `use` is a function, so an action is not plain data, and a snapshot holds the battle's state rather than
  its history.

---

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