En Banc Review

En banc — French for "on the bench" — describes a session in which a case is heard by the full membership of an appellate court rather than by a smaller rotating panel. The procedure exists primarily in courts that ordinarily decide cases in panels of three or so judges, and it is used to resolve questions of exceptional importance or to reconcile conflicting decisions within the court itself.

In the United States federal system, en banc review is governed by Rule 35 of the Federal Rules of Appellate Procedure, which states that such rehearing is "not favored" and ordinarily will not be ordered unless it is necessary to secure or maintain uniformity of the court's decisions, or the proceeding involves a question of exceptional importance. A majority of the active circuit judges must vote in favor. The Ninth Circuit, because of its size, uses a "limited en banc" panel of 11 judges rather than convening all active judges, under 28 U.S.C. § 46(c).

Other jurisdictions use analogous mechanisms. The Court of Justice of the European Union sits as a Grand Chamber of 15 judges for particularly complex or significant matters under Article 16 of its Statute. The European Court of Human Rights refers cases to a Grand Chamber of 17 judges under Article 43 of the European Convention on Human Rights. The UK Supreme Court can convene enlarged panels of seven or nine Justices for cases of constitutional importance.

For researchers and MUN delegates, en banc (or its equivalents) is a useful signal: when a court reaches for the procedure, it is flagging that the legal question is unsettled, politically charged, or doctrinally significant. Such decisions tend to carry greater precedential weight than ordinary panel rulings and often shape downstream litigation, regulatory practice, and even legislative responses.