A: It a piece of paper that orders you to come into court and give relevant testimony about a particular case. What if you don't want to go? In a civil case, a subpoena is a quasi-order, usually signed by an attorney. Sometimes a judge will sign the subpoena. You must go. If you don't you're subject to fines, sanctions, and possibly a visit by the local sheriff to your home or office. A subpoena is a way to get a witness into court to testify.