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 South Dakota, an offer of proof is a procedural tool used during a trial to create a record of evidence that the court has deemed inadmissible. 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 what the evidence would have shown and why it is relevant and material to the case. A bill of exceptions, on the other hand, is a more formalized method used to preserve a record for appellate review when an offer of proof was not made during the trial. It involves preparing a written statement detailing the evidence that would have been presented, which is then submitted to and approved by the trial judge. Both procedures are important for ensuring that a party can challenge the exclusion of evidence on appeal, and they are governed by South Dakota's rules of civil and criminal procedure as well as relevant case law.