Welcome to Principia
Principia is a physics-based sandbox game. Build and play advanced contraptions, circuiting, minigames, puzzles, robot adventures and more. Open source, free and available for Windows, Linux, Android and more, download it today.
This site is the new community site for Principia. When you have installed Principia, enjoy the levels others have created, and register in order to upload your own levels and interact with the community.
Want to read more about Principia?
Also check out...
And the Official community site archive, an archive of old levels spanning from 2013 to 2018.
Apparatus player? Check out Principia for Apparatus Players on the Principia Wiki!
Featured levels
Latest news More
- 6 Jul 2025Follow Principia on YouTube
- 14 Apr 2025New contest: Puzzling Puzzles
- 5 Apr 2025Principia 2025.04.05
- 22 Mar 2025Please help to test Principia
- 1 Aug 2024New contest: Destruction Frenzy
Top rated levels More
Latest custom levels More
Latest adventures More
Latest puzzles More
Glados commented on Adjustable FPS: 3 days ago
@Galaxium I guess you'll have to change the 60 to 120 in the codeGalaxium commented on Adjustable FPS: 3 days ago
Uh, my device natively runs at 120, so I think it's a lil broken :,)BobMonkeypimp2 commented on bottle factory: 5 days ago
That's cool.MEMORY_LOST commented on Bouncy World: 8 days ago
i like how the lua joins them too lolMEMORY_LOST commented on useless engine: 12 days ago
That wire tirck to connect engine to wheel is useful :)Galaxium commented on big car: 12 days ago
Very... Torquey :)BobMonkeypimp2 commented on Speed of light: 16 days ago
I think even with Lua, the fastest 'tick' in Principia is 16 milliseconds.BobMonkeypimp2 commented on Drag Racing Competition: 16 days ago
Very good :)