Pre-trial depositions are a routine but critical part of litigation practice. They preserve evidence and develop a record for summary judgment, settlement or trial. In some instances, lawyers can even be admonished by the court for not properly preparing a witness to testify.

There are a number of rules of civil procedure governing what happens during a deponent's testimony or afterward. Moreover, for lawyers, there are additional ethical considerations for preparing witnesses for their deposition. A recent opinion from the ABA Standing Committee on Ethics and Professional Responsibility (Formal Opinion 508) recognized that, while "the failure adequately to prepare a witness would in many situations be classified as an ethical violation," what a lawyer can do during witness-preparation is governed by the rules of professional conduct.