The engine & editor
s&box is built on Valve's Source 2, with a modern editor and a full set of creation tools.
The visual editors
ShaderGraph
Author shaders visually — a node graph that compiles to real shader code, with a live 3D preview.
ActionGraph
Visual scripting for game logic — wire up behaviour without writing C#, or drop into code anytime.
Source 2 rendering
A modern PBR renderer with post-processing, tonemapping, and physically-based materials out of the box.
Editor screenshots from the official s&box docs (CC-BY-4.0).
Everything in the box
Hotload
C# code changes take effect instantly — no recompiling or restarting the game.
Scene system
A GameObject/component scene model, familiar if you've used Unity or Godot.
ActionGraph
Visual scripting for logic without writing code.
ShaderGraph
Node-based shader authoring.
Map editor (Hammer)
Source 2's Hammer editor for building maps, plus a terrain system for open worlds.
Cloud assets
Drag-and-drop assets from the cloud — no manual downloading or subscribing.
Built-in multiplayer
Networking is built in; party up with friends without hosting a server.
VR support
Create and play in VR.
Going deeper
Each tool has its own documentation — including ActionGraph nodes, ShaderGraph, the Hammer map editor, and the terrain system — maintained on the developer wiki. Because the engine source is open under the MIT License, you can also read the implementations directly on GitHub.
Community wiki — not affiliated with Facepunch Studios. For the latest and most authoritative information, see the official developer wiki.