Copyright protects only the particular manner of an author’s expression in literary, artistic, or musical form. Copyright protection does not extend to any idea, system, method, device, or trademark material involved in the development, merchandising, or playing of a game. Once a game has been made public, nothing in the copyright law prevents others from developing another game based on similar principles.
Some material prepared in connection with a game may be subject to copyright if it contains a sufficient amount of literary or pictorial expression. For example, the text matter describing the rules of the game, or the pictorial matter appearing on the gameboard or container, may be registrable.