As the California Supreme Court has recognized, amici curiae can play a “valuable role” in litigation. (Connerly v. State Personnel Board (2006) 37 Cal.4th 1169, 1177.) “[B]ecause they are nonparties who often have a different perspective from the principal litigants[,]” their arguments “enrich[ ] the judicial decision-making process.” (Ibid.) Amicus filings are on the rise, and not just in the U.S. Supreme Court. However, with this increased volume has come an increased number of unhelpful and poorly written briefs. Governing court rules reflect this concern. For example, the U.S. Supreme Court advises:

An amicus curiae brief that brings to the attention of the Court relevant matter not already brought to its attention by the parties may be of considerable help to the Court. An amicus curiae brief that does not serve this purpose burdens the Court, and its filing is not favored.

(S. Ct. Rule 37.1.) Likewise, in California, amicus briefs must “assist the court in deciding the matter.” (Cal. Rules of Court, rules 8.200(c)(2) & 8.520(f)(3).) So, the question becomes how, in more practical terms, amici can help shape important decisions, aiding courts, rather than burdening them.

One way in which amici can provide quality assistance is by sharing unique perspective. For example, industry groups and individual businesses may be able shed light on the practical significance of a case’s potential outcomes for the impacted public, highlighting interests larger than those presented by the parties. Relevant scientific or statistical information—even if outside the trial record—may also aid the court. However, amici should generally avoid attempting to introduce case-specific information not found in the record.

Another good reason to file is when a party’s brief could use a modest assist. For example, amici often have a strong interest in just one of multiple issues raised in a case. The parties may be unable or unwilling to take a deep dive on that issue due to word limits, strategic concerns, or lack of expertise. An amicus brief can provide a more complete and detailed treatment, including an explication of the issue’s impact on the wider public.

An often overlooked use of amicus briefing is to guard against the truism that bad facts make bad law. Amici can help focus the court on the correct and just rule of decision—for example, by illustrating how a more sympathetic group of nonparties may be impacted. Also, although amici generally write in favor of one party or the other, it is also perfectly appropriate for amici to take a neutral stance on a case’s outcome, advocating instead for an opinion that provides clear guidance for the next case. For example, amici can suggest that a court explicitly identify case- and fact-specific limits on its ruling, or they may suggest that a court discuss specific counterfactuals that might have changed the outcome in the case under review. Both may help improve outcomes in future cases.

Finally, it is worth acknowledging that, while content should be amici’s primary concern, the form of a brief will also determine the extent to which it aids or burdens the court. Most importantly, amici should keep their briefs succinct. This is true of all good legal writing, but especially true of a brief that the court is not required to read. It is thus critical for amici to stay laser-focused on a single issue and the specific value they add to the court’s deliberations. The rest can and should be left to the parties. Using this approach, amici can truly be friends of the court.

Adam represents both public and private clients in civil writs, appeals, and mandate proceedings, as well as traditional litigation and dispute resolution. In addition, Adam is an adjunct professor teaching courses in local government and land use law at the University of San Francisco School of Law.