David Smith:

Good copying learns from another’s innovation and then applies it in a novel way to a new context in a way that doesn’t diminish the source invention.

Good stuff. This is something that has been on my mind as I've been working on an iOS game in my spare time. It's inspired by some of my favorite games, but it's also unique. Sometimes it's hard not to feel like people will look at it and say he just ripped this or that off another game. He is invalid. David Smith explains how you can take cues without 'ripping off'.