Take the following code snippet class Missile: instances = [] def __init__(self): Missile.instances.append(self) Now take the code: class Hero(): ... def fire(self): Missile() When the hero fires, a missile needs to be created and appended to the main list. Thus the hero object needs to reference the list when it fires. Here are a few solutions, although I'm sure there are others: Make the list a global, Use a class variable (as above), or Have the hero object hold a reference to the list. I didn't post this on gamedev because my question is actually more general: Is the previous code considered okay? Given a situation like this, is there a more Pythonic solution?