Rule 51 United States Federal Rules of Criminal Procedure
Rule 51 of the Federal Rules of Criminal Procedure is about Preserving Claimed Error. It is under Title IX (General Provisions) of the Rules.
(a) Exceptions Unnecessary. Exceptions to rulings or orders of the court are unnecessary.
(b) Preserving a Claim of Error. A party may preserve a claim of error by informing the court—when the court ruling or order is made or sought—of the action the party wishes the court to take, or the party’s objection to the court’s action and the grounds for that objection. If a party does not have an opportunity to object to a ruling or order, the absence of an objection does not later prejudice that party. A ruling or order that admits or excludes evidence is governed by Federal Rule of Evidence 103.