Attorney client privilege is common law in the US. It protects the right of the client. For this law, a client feels secure. This law lowers the potential risk of having sensitive information fall into the wrong hands.
When established an attorney-client relationship there exists this law. This relation doesn’t exist until a lawyer agrees to represent the client. In the majority of cases, an attorney-client relationship is clear and liable. They have an agreement paper that includes payment method, even an oral agreement, and all about.
The privilege law protects client communications with the attorney. For example, suppose that client is speaking with a lawyer, her lawyer, about a matter involving a car accident that is under investigation. The lawyer asks his client whether he took any drug prior to driving, and the client silently nods his head in the affirmative. Although no words were exchanged, this communication between the client and his lawyer is clearly protected by the privilege.