An offer of proof—also known as an informal bill of exception—is a procedure available during trial for the presentation of evidence the trial court has excluded. An offer of proof is made outside of the jury’s presence and often after the judge has sustained an objection to the admissibility of the evidence.

A bill of exception—also known as a formal bill of exception—is a procedure that allows a party to complain on appeal about evidence that would not otherwise appear in the trial record (because there was no offer of proof made at trial) by detailing the evidence (testimony, etc.) that would have been offered if the trial court had allowed it.

In Nevada, an offer of proof is a procedural tool used during a trial when the court excludes evidence. It allows the attorney to create a record of what the evidence would have shown, had it been admitted. This is done outside the presence of the jury, typically after an objection to the evidence has been sustained by the judge. The purpose of an offer of proof is to preserve the excluded evidence for appellate review, by demonstrating how it was relevant and material to the case. On the other hand, a bill of exceptions is a more formalized document that outlines the evidence that was not allowed to be presented during the trial. This is used to formally object to the court's ruling on the evidence and is included in the record for potential appeal. Both procedures are important for ensuring that a party can challenge the trial court's evidentiary rulings on appeal. In Nevada, the specific rules and procedures for making an offer of proof or a bill of exceptions are governed by the Nevada Rules of Civil Procedure and relevant case law.