Playing in your game

Patterplay is how a compiled story reaches a player. You build your project to one .patterc bundle, and a Patterplay runtime loads it and plays it: handing your game a flat stream of beats (a line, a narration, a choice) that you render and drive however you like.

There’s one runtime per engine - a set of four equals (JS, Unity, Unreal, Godot), not approximations of each other: every one is checked against the same test suite, so the same story behaves identically everywhere, right down to the seeded random draws. All four are shipping and verified today, so “your engine” is a real, supported target, not a roadmap item.

Pick your engine

Engine	Language	Get it	Quickstart
JavaScript / Web	TS/JS	@patterkit/runtime (npm) or a patterplay.min.js drop-in	JavaScript & web →
Unity	C#	UPM package (git URL or Release tarball)	Unity →
Unreal	C++ / Blueprint	UE plugin	Unreal →
Godot	GDScript	Addon	Godot →

All four expose the same shape: build an engine from a bundle, open a flow, advance it one step at a time, present each step, and pass back the player’s choice. Learn that shape once on the play loop page and the per-engine quickstarts are mostly install notes and the local idiom.

What every runtime gives you

• The play loop: advance a flow, get line / text / gameEvent / choice / end steps, pick options. → The play loop
• Properties: read and write the story’s @patter / @scene state; supply your game’s @world values.
• Game Data & tags on every step: your typed cues, merged with defaults, ready to drive audio, animation, and quests. → Save/load & Game Data
• Save / load: serialise the whole run (position, state, visit counts, even the PRNG) and restore it later, in one call.
• Localisation: read resolved text in Embedded mode, or get ids in IDs-only mode and feed them to your own system; switch language live. → Localisation
• Closed captions: let players turn off the non-spoken cues inside dialogue; the runtime strips them while the line still fires so audio plays. → Closed captions
• Audio: if you record voice-over with Audio Folders, a tiny resolver maps each beat to its winning take (from a build-time manifest), no folder search shipped. → Audio
• A live state inspector: watch and edit a running engine’s @patter properties while you playtest, with type-aware editors and reset-to-default. Every engine ships one: an editor window in Unity and Unreal, an in-game panel in Godot, a drop-in DOM panel on the web. Like the debug link, it is a dev tool that stays out of shipping builds.
• Live refresh & debug: a localhost link to Patterpad. Saving in the editor pushes the new bundle into the running game without a restart (JavaScript today), and the game streams its cursor back for the editor to follow like a debugger. Every engine ships a client, and each is a dev-only tool that stays inert in a shipping build. → Live refresh & debug
• Structure introspection: walk the authored tree (scenes → blocks → snippets → beats) without playing, for editor / dev tooling. getOutline() returns the nested tree; getBeatSequence() the flat, document-ordered beats. → Structure introspection

The guarantee

Every Patterplay runtime passes the same shared test suite: a fixed set of cases covering expressions, full playthroughs, save/load round-trips, Game Data resolution, and locale fallback. Each case is checked on every engine and on every release. That’s what lets you write the story once and trust it everywhere.

Where to go next

• Just want it running? Jump to your engine’s quickstart above.
• Want to feel it first? Open the interactive tour (examples/projects/tour.patter) in Patterpad and Play from Start, it shows choices, selectors, properties, conditions, and closed captions live.
• Want the mental model first? Read The play loop.
• Need the deep JS API? The Engine API.
• Integrating save/load, Game Data, host events? Save/load & Game Data.