Like everything else in life, a lawsuit has a beginning, middle and end, but you won't get to the middle or end if you don't do the first steps right. A lawsuit starts with a complaint that names a defendant as the person at fault. If you're the named defendant, your first step is to file a written response to participate in the suit.
If you get sued, you'll need to prepare something called an "answer" and file it within the required time period to avoid a judgment by default.
Begin at the Beginning: Served with a Complaint
You're put on notice that you're being sued when you're served with a summons and complaint that list you as a defendant. The complaint identifies the person bringing the case and describes the situation at issue and your role in it. The summons tells you how many days you have to respond after service. You're said to be served when someone who is not a party to the lawsuit hands you a copy. In some cases, the person can serve you by leaving the document at your home or business or by mailing you the documents. The period in which you must respond begins when you receive the document.
Time to Act: Respond or Lose
Not every state has the same rules about lawsuits, so be sure you know and follow those of your jurisdiction. Generally, you have a period of 20 or 30 days to respond to the complaint. In this time frame, you must draft a response, sign it, file it with the court and serve a copy on the other side. Failure to respond will not doom the complaint. Rather, if you do not participate in the suit, the other side can seek a default judgment. Usually, they will get what they ask for.
Response to Complaint: File an Answer
You can draft a response to the complaint (usually called an "answer") on your own, but it's often a good idea to consult an attorney. If you're doing it alone, check whether your state has a form that you can use for the answer. In either case, you need to put your name and address at the top, then fill in the same caption and case number. If your states allows a general denial, you can simply write that you deny each fact in the complaint. Otherwise, you should go through each numbered paragraph in the complaint and either admit it if it's true, deny it or say that you do not know. You then sign and date the response.
Affirmative Defenses and Counterclaims
If you have specific reasons for thinking that the complaint is not valid, these are called affirmative defenses. You include these in numbered paragraphs below the response paragraphs. Be careful to be thorough since you waive some claims if you don't mention them here. If you have other claims against the other party, for which you seek money or other relief, you list those in the response document under the heading Counterclaims, which is essentially you suing them right back.
Demurrer and Other Motions
You can file a demurrer or motion to dismiss instead of an answer in many states and in federal court. This document essentially claims that the complaint doesn't present a valid cause of action against you. That is, if everything they wrote in their complaint were true, they still wouldn't be able to win.
For example, if the other party is suing for a debt you incurred 20 years ago, you might argue to the court that it's too late to bring that claim under the limitations period set out in the statute. Even if everything they say is true, they'll lose, because the statute of limitations has run out.