The Powder Toy is a free, open-source falling-sand physics sandbox game, written in C++ and SDL and first created by Stanislaw Skowronek in 2008. It lets you paint hundreds of simulated elements — powders, liquids, gases, metals, explosives and living things — onto a grid and watch them interact through a surprisingly deep real-time simulation of air pressure, heat and gravity. In it you can build anything from a simple water channel to a working in-game computer, an elaborate power plant or a spectacular chain of explosions, then share it with the community.

Key Features

• Hundreds of simulated elements — over 250 materials, each with its own physical behaviour, reactions and interactions with every other element.
• Realistic physics — continuous simulation of air pressure and velocity, heat transfer, gravity, electromagnetic effects and countless element-to-element reactions.
• Electronics and logic — build switches, sensors, lasers and programmable circuits; players have even assembled working CPUs and text displays entirely in-game.
• Lua API and modding — automate builds, add entirely new elements, or install community plugins through the built-in scripting API.
• Community save sharing — browse and play thousands of player-created saves, rate them, and upload your own creations for others to try.
• Advanced toolset — brush, scratch, stamp, property and simulation tools, render filters, a full-featured in-game console, and paste/undo support.
• Truly free and open source — licensed under the GNU GPL version 3, developed on GitHub and actively maintained by a community that has kept it alive and updated since 2008.

Why Use The Powder Toy?

It is one of the best ways to play with physics, heat and electronics without any cost or risk — a “digital chemistry set” that runs as fast as your imagination. Because the whole game is free, ad-free and open source under GPL-3.0, and because it exposes a Lua scripting API, it suits everyone from casual players and students to hobbyists who want to build real in-game machines and even experiment with modding the engine itself.

Use Cases

• Casual sandbox play — draw water, fire, sand and explosives, then watch realistic reactions unfold.
• Learning physics and chemistry — explore heat transfer, air pressure, gravity and element reactions visually.
• Building electronics — design logic circuits, sensors and even calculators and simple computers.
• Modding and scripting — use the Lua API to add custom elements, plugins and automated builds.
• Community creations — explore, vote on and remix thousands of saves shared by other players.

Platform

Windows · macOS · Linux · Android (web and source builds also available)

Licence

GPL-3.0

Website

powdertoy.co.uk · GitHub repo

Similar Open-Source Sandbox

If you enjoy this kind of open sandbox with logic and automation, try Mindustry — another open-source sandbox built around building factories, turrets and automated production lines.

type: installable; _twif_self_hostable: omitted (games is an installable category, not server software — the field is intentionally not set)