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
- 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
- 12 Jul 2024Principia 2024.07.12
Top rated levels More
Latest custom levels More
Latest adventures More
Latest puzzles More
MEMORY_LOST commented on Raycast Renderer, more colors and a diferent control system: 13 days ago
this is amazing, try adding shadows or different colors for each side of the wall so the corners are more visible.MARRA92-AGAIN commented on lag: 13 days ago
spawns 1 wood cornerBobMonkeypimp2 commented on Raycast Renderer, more colors and a diferent control system: 15 days ago
Honestly, I preferred the orginal controls. I find the tiny joystick too fiddly.owhame commented on Efficient Two Stroke Water Engine: 15 days ago
Awesome and interesting 👏👍 (Can someone tell me how I can send steps from Android?)BobMonkeypimp2 commented on Efficient Two Stroke Water Engine: 16 days ago
I think that's probably one of the best water engines I've seen on Principia 😄Galaxium commented on Raycast Renderer: 16 days ago
Actually Baldis Basics might be easier? IdkGalaxium commented on Raycast Renderer: 16 days ago
Forget doom, what about halflifeowhame commented on I accidentally discovered something: 18 days ago
One of the few useful or interesting bugs in the game😂