The Attorney-Client Privilege

The attorney-client privilege facilitates open communications between attorneys and their clients1. The law recognized long ago that clients would be reluctant to reveal information to an attorney if the communications were subject to discovery. Yet for the attorney to properly advise a client, the attorney must receive complete and accurate information.
The attorney-client privilege is a powerful tool in protecting a client's legal interests. See e.g. The Early Steps To Take In Litigation. However, there are some essential things that every client should know about the attorney-client privilege.
First, it is a legal privilege: It is a right that allows a client to resist what would otherwise be a legally compelled disclosure of information2. In our legal system, laws make providing information mandatory under certain circumstances. A typical example would be a subpoena ordering a person to appear in court or at a deposition to give testimony. A person giving testimony is usually obligated to answer all questions truthfully. Failure to do so can have legal consequences, including fines and jail time. However, a person may refuse to answer a question based on a legally recognized privilege. The attorney-client privilege is one such privilege3.
Second, the attorney-client privilege is not absolute. There are limitations. One of the most common exceptions is the crime-fraud exception1. In California, this means seeking or obtaining the services of an attorney to enable or aid anyone in the commission of a crime or fraud will eliminate the attorney-client privilege4.
Third, a client may waive the attorney-client privilege by disclosing attorney-client communications5. Specifically, suppose the client, without coercion, reveals all or a significant part of a communication with the client's attorney or has consented to disclosure of the communication: This will be a waiver of the privilege, meaning that the client will not be able to use the privilege as a justification to withhold information.
So, when using the services of an attorney, take full advantage of the protection offered by the attorney-client privilege to give complete and accurate information to the attorney. You should always check with your attorney about the limits of the attorney-client privilege, which may apply in your particular situation. However, in general, so long as you are not using the attorney's services to commit fraud or a crime and keep all communications with your attorney confidential, the communications between you and your attorney should be free against compelled disclosure under the law.