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
owhame commented on mordan car: 15 hours ago
I love its realistic details.👍😂A completely environmentally friendly car!😂
MEMORY_LOST commented on Dirt bike: 7 days ago
@BobMonkeypimp2 thank you! these "pop and bang" sounds idea was inspired by my friend's scooter (these motorbikes that don't look a scooter)😂BobMonkeypimp2 commented on Dirt bike: 7 days ago
I like it. I like the electronic rear suspension and the engine sound (with pops and bangs). Handles well too.BobMonkeypimp2 commented on Absolute Confusion.: 7 days ago
@Glados I never noticed that! That fully explains the glitch.Glados commented on Absolute Confusion.: 7 days ago
Nvm, I did. Removing the cam targeter and activating "Disable cam movement" seems to fix itGlados commented on Absolute Confusion.: 7 days ago
@BobMonkeypimp2 I think might be on both your sides. I couldn't get it to glitch at allkacperTMPL commented on Goofy slow piston vehicle: 9 days ago
Yea it's smooth just by using two id fields and just a switch, as simple as it's possibleGalaxium commented on Absolute Confusion.: 9 days ago
Lol ig this level is all sorts of weird