(1) Before or at the Close of the Evidence. At the close of the evidence or at any earlier reasonable time that the court orders, a party may file and furnish to every other party written requests for the jury instructions it wants the court to give.
(2) After the Close of the Evidence. After the close of the evidence, a party may:
(A) file requests for instructions on issues that could not reasonably have been anticipated by an earlier time that the court set for requests; and
(B) with the court’s permission, file untimely requests for instructions on any issue.
(b) Instructions. The court:
(1) must inform the parties of its proposed instructions and proposed action on the requests before instructing the jury and before final jury arguments;
(2) must give the parties an opportunity to object on the record and out of the jury’s hearing before the instructions and arguments are delivered; and
(3) may instruct the jury at any time before the jury is discharged.
(1) How to Make. A party who objects to an instruction or the failure to give an instruction must do so on the record, stating distinctly the matter objected to and the grounds for the objection.
(2) When to Make. An objection is timely if:
(A) a party objects at the opportunity provided under Rule 51(b)(2); or
(B) a party was not informed of an instruction or action on a request before that opportunity to object, and the party objects promptly after learning that the instruction or request will be, or has been, given or refused.
(d) Assigning Error; Plain Error.
(1) Assigning Error. A party may assign as error:
(A) an error in an instruction actually given, if that party properly objected; or
(B) a failure to give an instruction, if that party properly requested it and -- unless the court rejected the request in a definitive ruling on the record -- also properly objected.
(2) Plain Error. A court may consider a plain error in the instructions that has not been preserved as required by Rule 51(d)(1) if the error affects substantial rights.
Rule 51 manages the jury-instruction process and, crucially, how instructional errors are preserved for appeal. Parties may request instructions at the close of the evidence (or earlier if the court sets a time), with limited room for later requests on issues that couldn't have been anticipated. Before instructing the jury and before final arguments, the court must inform the parties of its proposed instructions and give them a chance to object on the record, out of the jury's hearing.
To preserve a claim of error, a party must object distinctly, stating the matter and the grounds, at that opportunity (or promptly after learning of a late instruction). A party may then assign as error an instruction given over a proper objection, or the failure to give a properly requested instruction. Even an unpreserved error may be reviewed under the narrow plain-error doctrine if it affects substantial rights.