Federal Rules of Criminal Procedure
Fed. R. Crim. P. 52 - Harmless and Plain Error
(a) Harmless Error. Any error, defect, irregularity, or variance that does not affect substantial rights must be disregarded.
(b) Plain Error. A plain error that affects substantial rights may be considered even though it was not brought to the court’s attention.
(As amended Apr. 29, 2002, eff. Dec. 1, 2002.)