How can you copyright the rules of a game?

Answer 1

Copyright does not protect the idea for a game, its name or title, or the method or methods for playing it. Nor does copyright protect any idea, system, method, device, or trademark material involved in developing, merchandising, or playing a game. Once a game has been made public, nothing in the copyright law prevents others from developing another game based on similar principles. Copyright protects only the particular manner of an author's expression in literary, artistic, or musical form.

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.

The back side of this form letter describes the options for registering copyrightable portions of games. If your game includes any written element, such as instructions or directions, we recommend that you apply to register it as a literary work. Doing so will allow you to register all copyrightable parts of the game, including any pictorial elements. When the copyrightable elements of the game consist predominantly of pictorial matter, you should apply to register it as a work of the visual arts.

Source: United States Copyright Office

http://www.copyright.gov/fls/fl108.html