Abstract: The formal definition of error in common-law litigation is specific and narrow: error occurs when an institutional actor, usually a court, violates a procedural rule. This focus on process rather than outcome is a central element of the American adversarial system's commitment to procedural justice. Our system is based on the belief that justice is best served by using established procedures to decide every dispute, not by trying to achieve the best result in each individual case. This focus on procedure means the law can be harsh. The bank is entitled to foreclose on the poor widow and her orphans; even an unintended and improbable death turns an assault into manslaughter; and so forth. There's nothing novel in the notion that the law must be uniformly applied even if it sometimes produces unfortunate results. Non-lawyers may not always like these results, but they understand the purpose of adherence to general rules and accept it: 'It's The Law'. That's not what concerns us here. This essay focuses on a different aspect of American proceduralism: not the rules that regulate conduct in the world at large, but those used in court, after the fact, to determine what happened in some contested event. The official ideology of the American legal system is that the procedure used to decide facts is more important than the accuracy of the decision-that a verdict may be absolutely correct legally even if it is absolutely wrong factually. This procedural focus is at odds with common intuitions about the goals of law, inconsistent with the actual conduct of courts, and in conflict with the general professional wisdom on what legal error means in practice. really This brief essay focuses on review for error in mid-level American courts of appeal, courts whose primary mission is to resolve particular disputes rather than decide issues of general law. We begin with the official account of American appellate practice and briefly describe the system in its own terms. Next we sketch an alternative method of review for error, a simplified and idealized version of the procedure in continental civil-law systems. We then qualify our initial description of review in American courts: reality, of course, does not entirely correspond to the procedural ideal; in practice courts often do care about factual accuracy and material justice, even if they don't admit it. We follow with a comment on our lack of originality: our cynical description of appellate review is so well known it's nearly official dogma. We conclude with some speculations on the structural and cultural significance of our legal system's ambivalence, if not hypocrisy, about the importance of factual accuracy in review for error.