Writing for a unanimous court, Justice Ruth Bader Ginsburg held that a patent fails to comply with this requirement when the patent's claims, read in light of the specification and the prosecution history, "fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention."

In 2013, the United States Court of Appeals for the Federal Circuit reversed Judge Hellerstein's ruling.

On January 10, 2014, the Supreme Court granted Nautilus's request for review and oral argument occurred on April 24, 2014.

The Court acknowledged that this requirement must strike a "delicate balance" between the "inherent limitations of language" and the expectation that the public have notice of what exactly falls within the scope of the patent so as to avoid a "zone of uncertainty" that deters lawful conduct.

§ 112 ¶ 2 when the patent's claims, read in light of the specification and the prosecution history, "fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention."

The Court went on to reject the Federal Circuit's interpretation of Section 112, Paragraph 2 that had held that a claim was indefinite only if it was "insolubly ambiguous".

[10] Ronald Mann of SCOTUSblog remarked that, while the decision did seem likely to push the Federal Circuit to raise the standard for definiteness, he "doubt[ed] that many members of the patent bar will find much of clarification in the Court’s opinion.

"[11] Jason Rantanen at PatentlyO identified at least one post-Nautilus decision from the Federal Circuit that had, in his view correctly, held that "Nautilus changed the law of indefiniteness" and imposed a stricter standard.

[12] Other commentators similarly noted the impact that the decision had in expanding the range of indefiniteness challenges being brought by patent defendants.