Facepunch's modern game engine and creation platform — a successor in spirit to Garry's Mod.
s&box (stylised lowercase, pronounced “Sandbox”) is a game engine and creation platform built by Facepunch Studios — the studio behind Garry's Mod and Rust, founded by Garry Newman. It is built on Valve's Source 2 engine, with game code written in C# on .NET.
It launched publicly on Steam on April 28, 2026 (App ID 590830, $19.99). Facepunch released the engine's source under the MIT License in November 2025, though the underlying Source 2 code remains proprietary.
In late March 2026, Facepunch reached an agreement with Valve that lets creators export projects from s&box and publish them as standalone games on Steam — described as entirely royalty-free. Alongside this, developers can monetise in-platform via a system Facepunch calls the “playfund”.
Reception at launch has been mixed. Some reviewers and players have questioned the “spiritual successor to Garry's Mod” framing and the presence of microtransactions, and there has been notable criticism around AI-generated content appearing in community games. Facepunch has said it would act to push low-effort AI content off the front page.
For live review scores and player counts, see the Steam store page — this wiki doesn't reproduce those numbers because they change continuously.
Community wiki — not affiliated with Facepunch Studios. For the latest and most authoritative information, see the official developer wiki.
