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

Glados commented on Adjustable FPS: 3 days ago

@Galaxium I guess you'll have to change the 60 to 120 in the code

Galaxium 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 lol

MEMORY_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 :)