Inspector Varables

Is there anyway to add custom variables to a gameobject without a script? I remember reading someing about it but im not sure.

thanks

No, not without a script. However you can make custom inspectors with an editor script, where you can make all sorts of gui controls regardless of if there's an variable for it or not.

The gameobject class itself can't be changed. You can't even create a class that derives from GameObject because it's sealed. Besides that it would be against the strategy pattern ;)

You could of course implementing a custom editor for the GameObject class but that would break the nice default GameObject header in the inspector. The whole philosophy of scripting in Unity is based on the fact that you write behaviour scripts to extend the basic functionality of GameObjects and the built in components.

So the short answer to your question is: no.

I don't see a way , but why even do that? What are you trying to accomplish?