To help illustrate the terms and concepts you will often encounter in discussions of the Supreme Court, we have followed an imaginary Supreme Court case through the judicial process.

Suppose that the plaintiff (Mr. Lyon) is suing the defendant (his employer, the state-run Animal House Zoo). Mr. Lyon, who is white, scored higher than Mr. Behr, who is black, on an exam that qualifies employees for promotions. When the exam was scored, however, the zoo threw out the results because it worried that promoting a white candidate over a black candidate would leave it vulnerable to allegations that it had violated Title VII of the 1964 Civil Rights Act, which prohibits racial discrimination in employment. Mr. Lyon sued the Animal House Zoo, arguing that by throwing out the results of the exam, the zoo violated under his rights under Title VII and the Equal Protection Clause of the U.S. Constitution. (The Supreme Court addressed a case with similar facts in 2009 when it decided Ricci v. DeStefano.)

Here, we’ll look at the life of our hypothetical case, Lyon v. Animal House Zoo, focusing on proceedings in the Supreme Court.

Lower courts

Mr. Lyon is suing his employer, the Animal House Zoo, because he believes that the zoo violated his rights under the Civil Rights Act and the U.S. Constitution. He begins his lawsuit by filing it in the federal district court, the trial court responsible for considering federal cases in the area where he lives and works. After hearing arguments and receiving evidence from both Mr. Lyon and the zoo, the district court decides that the zoo did not violate Mr. Lyon’s rights.

Unhappy with the trial court’s decision, Mr. Lyon appeals it to the U.S. Court of Appeals for the 2nd Circuit, one of 13 federal appellate courts that review appeals from federal district courts. A panel of three randomly assigned judges reviews the case and affirms the district court’s ruling that the zoo cannot be held liable for its actions, because by throwing out the exam results, it had simply been trying to fulfill its obligation not to discriminate under the Civil Rights Act.

At this point, Mr. Lyon has to choose between petitioning the Supreme Court for review of the 2nd Circuit’s decision or seeking rehearing by the three judges or by all the judges on the 2nd Circuit. Mr. Lyon chooses to ask for rehearing by all the 2nd Circuit judges, known as en banc review, but the court denies his request.

Petition for a writ of certiorari

From the day the 2nd Circuit denies his petition for rehearing en banc, Mr. Lyon has 90 days to file a petition for a writ of certiorari (often called a cert petition), which is a brief asking the Supreme Court to hear his case. (If Mr. Lyon had won in the lower courts, the zoo could have filed a cert petition.) In most circumstances, the Supreme Court has discretion whether or not to grant review of a particular case. Of the 7,000 to 8,000 cert petitions filed each term, the court grants certiorari and hears oral argument in only about 80. Granting a cert petition requires the votes of four justices.

Mr. Lyon can request that the time for filing his cert petition be extended for up to 60 days. At least 10 days before the due date (absent extraordinary circumstances), he can file a motion requesting more time. That request would go to the circuit justice, the member of the Supreme Court responsible for the 2nd Circuit, currently Justice Ruth Bader Ginsburg. The justices vary in their willingness to grant extension requests.

In his cert petition, Mr. Lyon sets out the facts, the history of the case and the reasons why the Supreme Court should review the 2nd Circuit’s ruling. He tells the court that it should grant review not only because the 2nd Circuit’s opinion is wrong but also because, by doing so, the court can clarify ambiguities in both the Civil Rights Act and the Constitution. (In addition to focusing directly on the legal questions at issue in the case, cert petitions often point to disagreements among the federal courts of appeals about those issues and ask the Supreme Court to resolve those disputes by setting a precedent that the lower courts must follow.)

Once Mr. Lyon’s cert petition is filed, the zoo has three options: It can acquiesce, which means that it can agree with Lyon that the court should grant certiorari (opt to hear the case); it can waive its right to file a response to the cert petition (although the justices, after reading the petition, could still ask the zoo for its response); or it can file a brief in opposition (BIO). The zoo chooses the third option; once the cert petition is placed on the Supreme Court’s docket, the zoo has 30 days to file its BIO.

That deadline can be extended as well by making a request to the clerk’s office. One request will be granted as a matter of right. Later requests generally require the petitioner’s permission. There is no limit on the number of extensions. Because it agrees with the 2nd Circuit’s decision and wants that ruling to prevail, the zoo argues in its BIO that the court should deny Mr. Lyon’s cert petition and choose not to hear the case.

After the BIO has been filed, Mr. Lyon can file a reply brief, rebutting the points made by the zoo in the BIO and reiterating the arguments made in his cert petition. Unlike the cert petition and the BIO, which must be filed with the court under strict deadlines, the exact timing of the reply brief varies. A general rule of thumb, though, is that a reply brief should be filed approximately 10 days after filing of the BIO.

Before the court decides whether to hear Mr. Lyon’s petition, outside groups with an interest in the outcome of the case can file briefs telling the court why it should grant certiorari. These groups are known as amici curiae, which is Latin for “friends of the court”; the briefs they file are called amicus briefs. At the certiorari stage, when the court is deciding whether to hear a case, amicus briefs are normally only filed by those who agree with the petitioner that the court should review the case.

Once all of the cert stage briefs — the cert petition, the BIO (if any), the reply brief (if any) and the amicus briefs (if any) — are filed, they are distributed to the justices’ chambers. Seven of the current justices participate in the cert pool, which is a labor-saving device in which a cert petition is first reviewed by one law clerk in one of the seven chambers. That clerk prepares a memorandum about the case that includes an initial recommendation as to whether the court should review the case; the memorandum is circulated to all seven chambers, where it is reviewed by the clerks and possibly the justices there. Justices Samuel Alito and Neil Gorsuch do not participate in the cert pool. Instead, their law clerks review the incoming cert petitions on their own and make recommendations directly to their respective justices.

Based on these reviews, the justices decide to add Lyon v. Animal House Zoo to the discuss list, a short list of cases they plan to talk about at their next private meeting, or conference. (If no justice had asked to add Lyon to the discuss list, it would have been put on the “dead list,” and certiorari would automatically have been denied without the justices having ever discussed the case or voted on it.) At least four justices vote to grant review in Lyon, and the court announces this decision as part of an order list, which will generally be released on the Monday morning after the conference.

Merits stage

Once the court has accepted the case, the parties are required to file a new set of briefs. Unlike the cert stage briefs, which focused on whether the court should review the case, the briefs on the merits allow each party to explain why he or she should win the case. Once certiorari is granted, the petitioner generally has 45 days to file his opening brief. (This time frame is typical, but can vary in particularly time-sensitive cases; when the court was considering the dispute between presidential candidates George W. Bush and Al Gore, for example, it instructed the parties to file their merits briefs over the course of a single weekend. Also, depending on the court’s schedule, the parties to a merits case may be able to agree on a briefing arrangement that provides them with more time that the rules specify.) Mr. Lyon has a maximum of 50 pages in which to make his argument, and he uses that space to explain to the court why he thinks the Animal House Zoo violated his rights when it threw out the results of the promotional exam.

Even though the Supreme Court will be able to review the entire record in the case, Mr. Lyon and the zoo agree that it will be helpful for the justices to have ready access to the exam results, so they decide to file a joint appendix including this material. (If Mr. Lyon and the zoo had agreed that no joint appendix was needed, they could have filed a motion asking the court for permission not to prepare one.) Whoever loses the case will be required to pay for the printing of the joint appendix, so both Mr. Lyon and the zoo have an interest in keeping it as short as possible. The joint appendix is filed at the same time as Mr. Lyon’s merits brief.

A group not involved in Lyon v. Animal House Zoo, the United Coalition of Zoo Workers, learns about the case and decides that a Supreme Court ruling in Mr. Lyon’s favor will benefit its own mission. Therefore, the group files an amicus brief urging the Supreme Court to accept Mr. Lyon’s arguments; furthermore, it brings up some points that Mr. Lyon didn’t address in his brief, and that it thinks will be helpful in persuading the justices to rule in his favor. Because it supports the position of the petitioner, the coalition’s amicus brief is due one week after Mr. Lyon’s merits brief is filed. A would-be amicus must normally ask both sides for permission to file, but the court will almost always allow the filing of a timely amicus brief even if one side or another refuses to consent.

Thirty-five days after Mr. Lyon files his merits brief (absent an extension), the zoo’s brief, known as the respondent’s brief, is due. It is subject to the same 50-page limit as Mr. Lyon’s opening brief; the zoo uses the space to argue that, when it threw out the test results, it was only trying to avoid discriminating against any of its employees. The zoo argues that the 2nd Circuit’s interpretation of the case was correct, and it urges the Supreme Court to affirm, or leave in place, that ruling.

The U.S. government learns about Lyon v. Animal House Zoo, and it worries that a Supreme Court ruling in Mr. Lyon’s favor would restrict its own ability to promote its employees as it sees fit. Therefore, the government decides to file an amicus brief in support of the zoo. The U.S. solicitor general, who acts as the government’s lawyer in Supreme Court cases, files the amicus brief; her brief is due one week after the zoo’s brief is filed. The United States is one of a limited number of parties that do not have to ask for permission to file an amicus brief. The solicitor general also files a motion for divided argument, asking the Supreme Court to allot some time for her to speak as an amicus when the case is argued.

Once Mr. Lyon has filed his merits brief and the zoo has responded, Mr. Lyon has an opportunity to file a reply brief, which is due approximately 30 days after the respondent’s brief on the merits (but at least seven days before the case is argued). He uses this brief to rebut the arguments made in the respondent’s brief and the United States’ amicus brief and to reiterate the points he made in his original merits brief.

Oral argument

The Supreme Court normally hears oral arguments between October and April, scheduling them into monthly two-week sittings during which the court hears two (although sometimes one or three) arguments per day on Monday, Tuesday and Wednesday. Generally, the court allots one hour of argument time for each case, with each party speaking for 30 minutes.

Although amici often ask the court to grant divided argument — to let them use part of a party’s allotted half-hour to make their own points — these requests are rarely granted when they come from private groups. However, in Lyon v. Animal House Zoo, the court grants (as it often does) the solicitor general’s request for divided argument. Because the solicitor general will be arguing for the United States in support of the respondent, she (or another lawyer from her office) will be using 10 minutes of the half hour allotted to the zoo.

During the oral argument, the justices have the opportunity to ask the attorneys to clarify or elaborate on any questions that have arisen from the briefs. Frequently, much of the oral argument is devoted to answering these questions. Because Mr. Lyon is the petitioner, his attorney argues first. Mr. Lyon’s attorney speaks for 25 of the 30 minutes allotted to him, choosing to reserve the last five minutes for rebuttal. As soon as he finishes speaking, the attorney for the zoo has 20 minutes to respond. Following the zoo’s attorney, an attorney from the office of the solicitor general argues for 10 minutes on behalf of the United States, and then Mr. Lyon’s attorney uses his five remaining minutes to deliver a rebuttal.

Decision

Later that week, the justices hold a private conference during which they vote on how to decide the case. The senior justice in the majority (that is, either the Chief Justice or, if he is not in the majority, the justice who has been on the court the longest) decides who will write the majority opinion; if there is a dissent — a view held by a minority of justices that a different decision should have been reached — then the senior dissenting justice assigns one of the dissenting justices to write the dissenting opinion. If a justice agrees with the outcome of a case but not the reasoning behind it, he or she may write a concurring opinion, in which other justices may join. Justices may also write separate dissents. In the event of a tie vote — for example, if there is a vacancy on the court or if one of the justices has recused himself or herself from the case — the decision of the lower court remains undisturbed.

The assigned justices then draft and circulate opinions outlining their reasoning in reaching their decision. The time it takes to finalize an opinion depends on several factors, including how divided the justices are, which justice is writing the opinion, and the court’s schedule. Typically, all cases are decided by the time the court recesses for the summer at the end of June or the beginning of July.

The court announces its decision in Lyon v. Animal House Zoo in open court. Here, the court hands down, or issues, an opinion in which it reverses the 2nd Circuit’s decision, explaining its reasons for ruling that the 2nd Circuit was wrong to decide the case in the zoo’s favor and that it should have ruled in favor of Mr. Lyon instead. (Alternatively, the court could have affirmed the case, ruling that the 2nd Circuit was right and that the zoo should not be held liable, or it could have vacated the 2nd Circuit’s ruling, effectively canceling it, and remanded the case, directing the 2nd Circuit to re-examine it based on theories, evidence or reasoning it had not yet considered.)