Copyright law protects original works of authorship. But what happens when the work is based on another original work of authorship? A derivative work may be protected if it incorporates some or all of a preexisting work and adds new original copyrightable authorship. For example, an author's modification to standard superhero characters could be conceivably entitled to protection.
In this Los Angeles & San Francisco Daily Journal article, David Martinez and Tommy Du discuss a recent federal court decision that illustrates the contours of derivative work protection and underscores the difficulty in establishing derivative rights to comic book characters.