A civil action summons notifies you that you are being sued. A civil suit is a kind of duel. Modern American trial practice is a direct descendant of medieval trial by combat. These trials may be seen as contests to determine who is right. From the beginning, you must be prepared to defend yourself, and the moment you must begin your defense is the moment you are served with a summons.
Read the summons and all accompanying documents and take notes. Determine who is suing you, why, for what and how long you have to respond. The person suing you is usually called the "plaintiff," and you are the "respondent."
Draft a factual response to the allegations. The complaint must specify why you are being sued. If the complaint says you did X on a certain date and you did not, include that fact in your response.
Consult with an attorney to determine if there are areas of law that should be disputed in your response to the complaint, such as whether you were properly notified of the lawsuit. Ask the attorney what form you should use to file your response.
File a written response to the complaint on the proper form with the clerk of the court that issued the document within the time period specified on the summons. File any additional forms required by the court, such as a case information or cover sheet, and pay a fee, which varies by jurisdiction. You usually have 20 to 30 days to respond, but check the summons to be sure. Unless you file a written response, you may lose the lawsuit by default.
Send a written copy of your response by certified mail to the person who is suing you or to his attorney. In some jurisdictions, the response must be certified by the court clerk.
File a proof of service form, in some jurisdictions, with the court clerk to prove you have notified the plaintiff of your response. The cost for this filing also varies by jurisdiction.