Suppose that you write a brilliant software game program based on the latest
Stephen King’s novel and begin selling it.
What will happen? Unless you have a license from the holder of the rights to create computer games from the novel, you will surely be sued. This is because your software is a derivative work.
In copyright law, a derivative work is a fundamental concept. It means a work
based on another work. The legal rule on derivative works is quite clear and is
just what you would expect: If you want to create, make copies of or sell a derivative work, you need the permission of the holder of the rights that your work is based on.
If you create a derivative work without permission, you infringe the copyright
in the underlying work. Moreover, while you will have the copyright in
your derivative work, your rights will cover only your own contribution and
creation—and any acts to distribute the derivative work without permission
from the owner of the underlying work will be acts of infringement.
Examples of derivative works are a translation, a sequel or an adaptation of a
work for another medium—for example, a movie based on a novel.
A derivative software program could be:
An update, new release, or new version of any existing computer program,
A “localized” version of a program with foreign language content,
A “port” of a program into a different software-operating system,
A program substantially derived from another computer program (or portions of the program),
A program based on another medium such as a novel, a movie, or a game
that is copyrighted.
A novel, television show, or movie based on a digital product, such as a video
game, would also be a derivative work.
Processing works electronically also creates derivatives. For example, if you take a digital music file from a music CD and process it to create an MP3 file, you have created a derivative of the original file.
The concept of what is derivative is logically related to the concept of copyright
infringement. In contracts we often define a derivative work as: “A work sufficiently based on a copyrighted work such that copying it without permission would infringe the copyright of the prior work.”