Eurogamer writes: "Is it possible to copyright a game mechanic? Many have tried. At the dawn of videogame time, Magnavox sued Atari for copying its rudimentary tennis game to create Pong. More recently, social game developer Zynga, creator of FarmVille, sued rival Playdom for allegedly stealing the 'Zynga Playbook', a document outlining valuable concepts, techniques and best practices for developing successful online games. While the first case was settled out of court and the second continues today, as yet unresolved, the line between inspiration and plagiarism is a fine one, yet to be legally clarified with regard to videogames".