If the object creating the object is not the active world, then you need a reference to the active world to call addObject on. You may have the following: All instance (non-static) methods are executed on an object -- an instance of the class the class the method is in. That is, the following format holds: expressionGivingAnObject.methodName(); If no object is explicitly given, then, by default, it is implicitly assumed to be the same object that the calling method is being executed on (aka: 'this'). Since addObject is a World instance method, it must be executed on a World object. You can use the Actor instance getWorld method to get the World instance an actor is in:

I am trying to write code in the object classes to display the objects on the main world so in my example i have the cheeseworld and i am trying to add the mouse on cheeseworld so i am basically calling the mouse method in cheeseworld however i haven't made the code yet to add mouse so in that method would i be using addObject(new mouse(). 0,0); or do i need to add the getworld and where do i add that?

Sounds like you are trying to construct your world. That is, place the initial actors into your world. That would be coded in your World subclass, either in the constructor method or in a method called from that constructor (usually called prepare).