2D + 3D Game Engine

Ruzit

A Luau-scripted 2D and 3D game engine written in Rust, similar in spirit to love2d, but with Luau, a Roblox style API, real wgpu rendering, and a single ruzit build command that bundles your project into a self-contained launcher.

Quick Start API Reference GitHub Luau

What is Ruzit?

Ruzit is a single-file game engine you script in Luau. The engine itself is a Rust binary that ships every system a game needs, 3D renderer, 2D overlay primitives, audio, networking, asset loading, packaging, behind a Lua API designed to feel familiar if you've used Roblox Studio.

Both ends of the spectrum are first-class: build a flat 2D platformer with GUI.Basic primitives, a fully-3D scene with Renderable parts and models, or any mix, 2D primitives always render on top of the 3D scene. Same idea as LÖVE / love2d in that the engine stays out of your way; same idea as Roblox in that every API is typed and discoverable from one types.d.luau file.

You write your game as .luau files in a folder. The engine boots them as the entry point of a virtual scene graph; the same source runs unchanged inside a packaged executable shipped to players.

Build flags

Ruzit's runtime crate ships with three optional Cargo features. The default ruzit CLI build enables only the bare minimum; opt in to what your game uses by passing --features at compile time (or by listing them in your build.toml's features array when building a launcher).

Building from source with everything:

cargo build --release --features voice,steam

Or for a packaged game via the CLI:

ruzit build --features voice

Features that aren't compiled in fail loudly at the import boundary with a clear message (e.g. "voice feature is disabled in this build"), so you can ship a slimmer runtime without any silent-no-op surprises.

Quick Start

Scaffold a new project and run it in a handful of commands:

# Drop the ruzit + ruzitrun binaries side-by-side somewhere on your PATH, then:
ruzit init MyGame
cd MyGame
ruzit scaffold     # regenerate .luaurc aliases (run after adding/removing packages)
ruzit test

ruzit init writes a starter project to the named folder (build.toml, Main.luau, an empty assets/, a .luaurc with Game = "./", and .vscode/settings.json) and fetches a fresh types.d.luau from the master repo so autocomplete is always current. The scaffolded Main.luau opens a window, draws a cube, and exits on close — replace it with your game.

ruzit scaffold walks the project tree for any folder containing a ManagedInfo.toml and writes one .luaurc alias per package, pointing at the entry file. Run it whenever you add, remove, or rename a package so require("@PkgId") autocompletes in the editor.

The two binaries

Ruzit ships as a Cargo workspace producing two distinct binaries that you install side-by-side:

See CLI for the full command reference.

The eight commands

Hello world

The smallest meaningful Ruzit program:

-- Main.luau
local Window = import("Window")
local Renderable = import("Renderable")
local Vector = import("Primitives").Vector

local win = Window.Open({ Title = "Hello, Ruzit", Width = 1280, Height = 720 })

local cube = Renderable.BasePart("Cube")
cube.Size = Vector.new(2, 2, 2)

import is the global library accessor, it returns a typed handle to one of the engine subsystems. The Luau LSP follows the return type through every import("X") call, so hover docs and autocomplete work everywhere.

Architecture

Three layers, top to bottom:

A packaged game is the same engine binary with a JSON trailer pointing at Managed/*.managed. The launcher detects the trailer at startup and boots the bundled scripts instead of the CLI dispatcher, so the engine binary and the user's launcher are literally the same file.