What is "en banc"

adv. (context legal English): As a group, particularly with respect to a legal decision rendered by all of the judges sitting on a court, rather than by a smaller panel of judges from that court.

In law, an en banc session ( French for "in bench") is a session in which a case is heard before all the judges of a court (before the entire bench) rather than by a panel selected from them. The equivalent terms in banc, in banco or in bank are also sometimes seen.

En banc review is often used for unusually complex cases or cases considered to be of greater importance. Appellate courts in the United States sometimes grant rehearing en banc to reconsider a decision of a panel of the court (generally consisting of only three judges) in which the case concerns a matter of exceptional public importance or the panel's decision appears to conflict with a prior decision of the court. In rarer instances, an appellate court will order hearing en banc as an initial matter instead of the panel hearing it first.

Some appellate courts, such as the Supreme Court of the United States and the highest courts of most US states, do not sit in panels but hear all of their cases en banc (with the exception of cases where a judge is ill or recused). Outside the United States, true en banc sessions of appellate courts are rare or nonexistent.