A Washington Subpoena — To Appear and Testify at a Hearing or Trial in a Civil Action is a formal summons issued by a court requiring a person to appear and testify at a hearing or trial in a civil action. This type of subpoena is issued to individuals who are not parties to the lawsuit, usually witnesses who have relevant information about the case. There are two main types of Washington Subpoena — To Appear and Testify at a Hearing or Trial in a Civil Action. The first type is a subpoena ad testificandum, which orders the witness to appear and testify in court. The second type is a subpoena duces tecum, which orders the witness to appear and bring documents or other forms of evidence to court. Both types of subpoenas are legally binding, and failure to comply can result in legal consequences.