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

Top rated levels More

Latest custom levels More

Latest adventures More

Latest puzzles More

Latest comments

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 corner

BobMonkeypimp2 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 πŸ‘πŸ‘ (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 πŸ˜„

Galaxium commented on Raycast Renderer: 16 days ago

Actually Baldis Basics might be easier? Idk

Galaxium commented on Raycast Renderer: 16 days ago

Forget doom, what about halflife

owhame commented on I accidentally discovered something: 18 days ago

One of the few useful or interesting bugs in the gameπŸ˜‚