Substantial similarity

Substantial similarity, in US copyright law, is the standard used to determine whether a defendant has infringed the reproduction right of a copyright. The standard arises out of the recognition that the exclusive right to make copies of a work would be meaningless if copyright infringement were limited to making only exact and complete reproductions of a work. Many courts also use "substantial similarity" in place of "probative" or "striking similarity" to describe the level of similarity necessary to prove that copying has occurred. A number of tests have been devised by courts to determine substantial similarity. They may rely on expert or lay observation or both and may subjectively judge the feel of a work or critically analyze its elements.