Appellate review is limited, almost by definition, to consideration of the factual record as established in the trial court. Adhering to this record review principle, appellate courts generally reject out of hand any effort to supplement the appellate record with evidence that was not considered by the court below.

There are, however, exceptions to this traditional principle. Whether presented through amicus briefs, social-science-laden “Brandeis Briefs,” petitions for discretionary review, or other mechanisms for supplementing the record, appellate courts often consider and rely upon new evidence. The literature regarding both the traditional rule and the exceptions is limited, and neither courts nor commentators often discuss either the underlying record review principle or the rationales supporting consideration of new evidence on appeal.

This article fills that gap by examining the record review doctrine and the many exceptions to it. That examination reveals that the traditional rule is not a monolithic as our instincts suggest; rather, it is an historical accident, and the many exceptions to the rule suggest its underlying flexibility. Appellate courts should acknowledge that it is not unusual to consider new evidence on appeal, and begin to work toward an explicit balancing of the benefits of the traditional record review rule against the utility presented by considering new evidence in different procedural postures. By approaching this problem from a global, procedural perspective, appellate courts will not only improve and regularize the management of new evidence on appeal, but they may begin to address some of the long-acknowledged problems associated with some of the most significant new evidence of all: the legislative facts that are a critical part of appellate court lawmaking.