An appellate brief is the written legal argument a party files with a higher court asking it to reverse, modify, or uphold a decision from a lower court. Because appellate judges rarely hear witnesses or see new evidence, the brief is the main vehicle for the argument. It identifies the legal errors the party believes occurred below, points to where in the trial record those errors happened, and cites the statutes and cases that support a different outcome. In the federal system, what the brief must contain, how long it can run, and when it must arrive are set by the Federal Rules of Appellate Procedure, and most state courts follow a similar framework.
Who Files One and When
The appellant is the party who lost in the lower court and starts the appeal by filing a notice of appeal. That party files the opening brief, laying out the alleged errors and asking for reversal or modification. The appellee is the party who won below and files a response brief defending the ruling or arguing that any errors were harmless. After the response, the appellant may file a reply brief, which is optional but cannot raise new issues; it must address points the appellee brought up.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 28 – Briefs
When both sides want to challenge parts of the lower court’s decision, the appellee can file a cross-appeal. That shifts the sequence from three briefs to four, with combined response-and-cross-appeal filings replacing the usual back-and-forth.2Legal Information Institute. Federal Rules of Appellate Procedure Rule 28.1 – Cross-Appeals
Non-parties with a stake in the legal issues can also file an amicus curiae brief. Federal and state governments can do so without permission. Everyone else needs either consent from all parties or leave from the court, with an explanation of their interest and how the brief would help.3Legal Information Institute. Federal Rules of Appellate Procedure Rule 29 – Brief of an Amicus Curiae
What Goes Inside the Brief
Federal Rule of Appellate Procedure 28 sets out what an appellant’s brief must contain. The order and the specifics vary across jurisdictions, but most courts expect roughly these elements:
- A table of contents and a table of authorities listing every case, statute, and source cited.
- A jurisdictional statement explaining why both the trial court and the appellate court have authority over the case, with statutory citations.
- A statement of the issues presenting the specific legal questions the court is asked to answer.
- A statement of the case summarizing the facts and procedural history, drawn entirely from the trial record. No new facts are allowed.
- A summary of argument that previews the legal points in a few paragraphs. The federal rules require this to be more than a reproduction of the argument headings.
- The argument itself, with each issue in its own section, citations to authorities and the record, and the applicable standard of review.
- A conclusion stating the specific relief sought, such as reversal, a new trial, or a modified sentence.
An appellee’s brief follows the same general structure but can skip sections like the jurisdictional statement and the statement of the case if the appellee agrees with the appellant’s version.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 28 – Briefs
Standards of Review
Every issue in an appellate brief must identify the standard of review, which tells the court how much deference it owes the trial court on that point. Rule 28 requires the appellant to state the applicable standard for each issue, either within the discussion or under a separate heading.1Legal Information Institute. Federal Rules of Appellate Procedure Rule 28 – Briefs The three most common standards work very differently:
- De novo review means the appellate court looks at the question fresh with no deference. This applies to pure questions of law, such as statutory interpretation or jury instructions, and gives the appellant the best shot at reversal.
- Abuse of discretion means the appellate court defers to the trial judge and reverses only if the ruling was unreasonable or arbitrary. It applies to judgment calls like evidentiary rulings and discovery decisions.
- Plain error applies when the party did not object at trial, so the issue was not preserved. The appellate court reverses only if the error seriously undermined the fairness of the proceedings.
If every issue in your appeal falls under abuse of discretion or plain error, the brief has to work harder to overcome the deference the appellate court will give the ruling below.
Deadlines That Govern the Brief
The clock on an appeal starts with the notice of appeal, not the brief. In federal civil cases, the notice must be filed within 30 days of the entry of judgment. In federal criminal cases, that window is 14 days.4Legal Information Institute. Federal Rules of Appellate Procedure Rule 4 – Appeal as of Right, When Taken Missing this initial deadline generally forfeits the right to appeal.
Once the record from the lower court is filed with the appellate court, Rule 31 sets the briefing schedule:
- The appellant’s opening brief is due within 40 days after the record is filed.
- The appellee’s response brief is due within 30 days after the opening brief is served.
- The appellant’s reply brief is due within 21 days after the response is served, and at least 7 days before oral argument.
In a cross-appeal, the appellee has 30 days after the appellant’s principal brief to file its combined response and cross-appeal brief, and the appellant then has 30 days to respond and reply.2Legal Information Institute. Federal Rules of Appellate Procedure Rule 28.1 – Cross-Appeals State appellate courts set their own schedules, which can look quite different from the federal timeline.
Length and Formatting Limits
Appellate courts enforce brief length tightly. Under Rule 32, a principal brief cannot exceed 13,000 words. A reply brief is capped at 6,500. A brief that relies on the word-count option must include a certificate of compliance stating the word count.5Legal Information Institute. Federal Rules of Appellate Procedure Rule 32 – Form of Briefs, Appendices, and Other Papers As an alternative, the rules allow a page-based limit of 30 pages for a principal brief and 15 pages for a reply. Most practitioners use word count because it gives them more room.
The rules also specify typeface, margins, and binding. These feel bureaucratic, but a brief that ignores them can be rejected on arrival. State appellate courts set their own formatting requirements and may use different word or page limits.
What Happens If You Miss a Deadline
If the appellant fails to file a brief on time, the appellee can move to dismiss the appeal. If the appellee is the one who misses the deadline, the appellee loses the right to participate in oral argument unless the court grants special permission.6Legal Information Institute. Federal Rules of Appellate Procedure Rule 31 – Serving and Filing Briefs Many appeals quietly end this way. Courts sometimes issue warnings and set firm dismissal dates, but once an appeal is dismissed for failure to brief, reinstating it typically requires showing exceptional circumstances.
How Appellate Briefs Differ From Trial Filings
The core difference is that an appellate brief cannot introduce new evidence. Trial filings argue about what facts will be proved; an appellate brief works from the record already made below, including transcripts, exhibits, and prior filings. Federal appellate courts treat this as a firm rule and will not consider evidence or facts raised for the first time on appeal.
Narrow exceptions exist, such as judicial notice of publicly available facts or correction of the record under Rule 10(e), but these do not let you supplement the record with evidence you wish you had offered at trial. If important evidence was missing below, the usual remedy is to seek a remand so the trial court can consider it, not to attach it to the brief.
The audience also shifts. Trial documents speak to a single judge or a jury deciding what happened. An appellate brief speaks to a panel reviewing whether the law was applied correctly. The question moves from what the facts are to whether the lower court handled the law and procedure properly.
After the Briefs Are In
Once briefing is complete, the appellate court decides whether to hold oral argument. Under Rule 34, oral argument is the default; a three-judge panel can skip it only if the judges unanimously agree it would not help, usually because the appeal lacks merit, the law is settled, or the briefs cover everything.7Legal Information Institute. Federal Rules of Appellate Procedure Rule 34 – Oral Argument Parties can also agree to submit the case on the briefs alone.
Many federal appeals are decided without any oral argument at all. When argument does happen, each side gets a limited slot, often 15 to 30 minutes, and the judges will already have read the briefs. The questions tend to focus on the points the panel finds hardest. For almost every appeal, the written brief is where the case is won or lost.