Points of Law

How to Prove Copyright Infringement

Douglas Robbins
May 13, 2024
Green Matrix style code cascading down

Proof of copyright infringement requires plaintiff to show that she owns a valid copyright in the protected work; and (2) that defendant copied protected aspects of the work. Rentmeester v. Nike, Inc., 883 F.3d 1111, 1116–17 (9th Cir. 2018). The most significant fights in infringement lawsuits are (1) did the defendant have access to and copy the protected work; and (2) is the copied work the same or substantially similar to the copyrighted work.

Access & Copying

To prove the alleged infringer had "access" the plaintiff must show that the infringer could have conceivably seen the work and then actually copied it. Access alone is not enough. As the courts have explained, the inverse ratio rule is dead: “Access” to the copyright work “does not obviate the requirement that the plaintiff must demonstrate that the defendant actually copied the work.” Skidmore as Tr. for Randy Craig Wolfe Tr. v. Zeppelin, 952 F.3d 1051, 1069 (9th Cir. 2020).

Once the plaintiff proves that the alleged infringer accessed and copied the work then she must also prove that the copied work is exactly the same as the copyrighted work, or in the alternative that the copied work is substantially similar to the copyrighted work. If the copy is identical to the copyrighted work, then there is not much of a fight. More often, however, is when the copy is very similar to but not exactly the same.

Substantial Similarity Test

“The substantial-similarity test contains an extrinsic and intrinsic component.” Id. at 1077. The Court applies the “extrinsic test,” an objective test based on specific expressive elements. Benay v. Warner Bros. Entm't, Inc., 607 F.3d 620 (9th Cir. 2010).

“In applying the extrinsic test, [the] court compares, not the basic plot ideas for stories, but the actual concrete elements that make up the total sequence of events and the relationships between the major characters.” Funky Films, Inc., 462 F.3d at 1077 (quotation omitted). Sequences of events that “flow naturally from generic plot-lines,” called scenes a faire are not protectable. Id. at 1077. Thus in determining substantial similarity under the extrinsic test, the Court “focuses on articulable similarities between the plot, themes, dialogue, mood, setting, pace, characters, and sequence of events in two works, and court must take care to inquire only whether the protectable elements, standing alone, are substantially similar.” Benay, 607 F.3d at 624.

In many cases, court will take a highly atomistic view filtering out elements that are either facts in the world, mere ideas, high-visibility themes, familiar plots, generic characters, or scenes a faire that necessarily follow from the story premise. By the end, there is often nothing left. As one commentator noted, “In short, after carving similarities down to the molecules, the courts [often will] find only unprotectable elements. These are then filtered out and disregarded, leaving nothing to satisfy the extrinsic test.” Robert F. Helfing, Substantial Similarity in Literary Infringement Cases, Westlaw J. Intell. Prop., at *1, Aug. 6, 2014. Under this analysis, proving substantial similarity is very difficult.

But in the Ninth Circuit, the Metcalf case and its progeny offers a more liberal interpretation of the extrinsic test, suggesting that a wholistic (not atomistic) approach may be appropriate in cases of infringement where there is a voluminous similarity—even if the individuated elements are not strictly protectable. Metcalf v. Bochco, 294 F.3d 1069, 1074 (9th Cir. 2002) (“The particular sequence in which an author strings a significant number of unprotectable elements can itself be a protectable element.”), overruled on other grounds by Skidmore as Tr. for Randy Craig Wolfe Tr. v. Zeppelin, 952 F.3d 1051 (9th Cir. 2020); see also Shaw v. Lindheim, 919 F.2d 1353, 1363 (9th Cir. 1990) (“Where plot is . . . properly defined as the sequence of events by which the author expresses his theme or idea, it constitutes a pattern which is sufficiently concrete so as to warrant a finding of substantial similarity if it is common to both plaintiff's and defendant's works.” (quotation marks and ellipsis omitted)), overruled on other grounds by Skidmore as Tr. for Randy Craig Wolfe Tr. v. Zeppelin, 952 F.3d 1051 (9th Cir. 2020).

But courts in the Ninth Circuit “routinely decline to apply Metcalf when two works' unprotected elements are not arranged in a strikingly similar fashion.” Esplanade Prods., Inc. v. Walt Disney Co., No. CV1702185MWFJCX, 2017 WL 5635027, at *16 (C.D. Cal. Nov. 8, 2017), aff'd, 768 F. App'x 732 (9th Cir. 2019); see, e.g., Shame on You Productions, 120 F. Supp. 3d at 1170; Gable v. Nat'l Broadcasting Co., 727 F. Supp. 2d 815, 843-44 (C.D. Cal. 2010), aff'd, 438 Fed. Appx. 587 (9th Cir. 2011) (“Here, in contrast [to Metcalf], many of the elements Plaintiff points out are not similar when viewed in context, and those that do bear some commonality—e.g., lottery winnings, prison time, paying off debts—do not occur in the same sequence.”); Bernal, 788 F. Supp. 2d at 1067 (“The elements that Plaintiff contends are similar are, in fact, markedly different when viewed in context. Further, Plaintiff has not pointed to any common pattern of unprotected elements that occur in the same sequence in both works.”); Zella v. Scripps Co., 529 F. Supp. 2d 1124, 1138 (C.D. Cal. 2007) (“Plaintiffs fail to point to any string of unprotected elements in Rachel Ray that resembles Showbiz Chefs in the sort of magnitude contemplated by the Metcalf court ... Courts have routinely rejected Metcalf claims over random similarities.”); see also Identity Arts v. Best Buy Enter. Servs. Inc, 2007 WL 1149155, at *17 (N.D. Cal. Apr. 18, 2007) (finding that “in Metcalf, the ‘many’ generic similarities and patterns present in the works in question were much more voluminous and specific than in this case”).

Thus the fight in a substantial similarity analysis is whether the court will apply the liberal Metcalf standard or the more strict Funky Films test. The success or failure of your lawsuit may depend on the law the court chooses to apply to your case.


Initial consultations are always free of charge.
Whether we engage as your lawyers or not, we always keep your
communications privileged and confidential.