These unprotectable components include idea (as contrasted with expression), scènes à faire (conventional elements typical of a genre), material in the public domain, and functional aspects.
As the Ninth Circuit explained in the 1988 Data East case, that such elements are common to two works does not create substantial similarity.
[3] This legal test has generally "been applied in subsequent [copyright law] decisions, to the extent that it is recognised in the USA, and elsewhere, as the accepted standard.
The US Supreme Court followed this approach in O'Reilly v. Morse and subsequent decisions including Parker v. Flook and Mayo v. Prometheus.
A similar type of analysis of obviousness or inventive level has been used under the name of the "point of novelty" test, which is suggested by the use of a Jepson claim.