The attorney-client privilege is an evidentiary rule that protects both attorneys and their clients from being compelled to disclose confidential communications between them made for the purpose of furnishing or obtaining legal advice or assistance. The privilege is designed to foster frank, open, and uninhibited discourse between attorney and client so that the client’s legal needs are competently addressed by a fully prepared attorney who is cognizant of all the relevant information the client can provide. The attorney-client privilege may be raised during any type of legal proceeding, civil, criminal, or administrative, and at any time during those proceedings, pre-trial, during trial, or post-trial.
The privilege dates back to ancient Rome, where governors were forbidden from calling their advocates as witnesses out of concern that the governors would lose confidence in their own defenders. In 1577 the first evidentiary privilege recognized by the English common law was the attorney-client privilege. The English common law protected the confidential nature of attorney-client communications, regardless of whether those communications took place in public or in private. The American colonies adopted this approach to the attorney-client privilege, and Delaware codified the privilege in its first constitution in 1776.