Options for Responding
In most states, you have three options for responding to a divorce complaint or petition. You can file an appearance, which tells the court you're neither contesting nor agreeing with your spouse's request for divorce, but want to be involved in decisions regarding custody, support or property. Your other choice is to file an answer to your spouse's divorce papers, denying her grounds or contesting her requests regarding custody, support or property. Lastly, you can file a counterclaim with your answer, which serves as your own complaint or petition for divorce.
Establishing Your Grounds
Because a counterclaim acts as your own complaint, it tells the court you also want the divorce. You can file on the same grounds your spouse did or elect to use different grounds of your own. If both you and your spouse file on your state's no-fault grounds, this tells the court you also believe your marriage is over. Alternatively, you might want to file on fault grounds if your spouse committed adultery or some other marital misconduct. You can do so, even if your spouse filed on no-fault grounds.
In some states, if you file just an answer to your spouse's divorce papers, you can only ask the court to deny what she's asking for. If you file a counterclaim instead, you can ask for your own relief. In legal terms, "relief" is what you're asking the court to give you. Therefore, if your spouse asks for custody and you file an answer and counterclaim in response, you can ask the court to deny her request in your answer and award you custody instead in your counterclaim. Because a counterclaim is its own separate document, you can also ask for relief your spouse didn't mention or didn't think to include in her petition or complaint.
Your Spouse's Response
When you file a counterclaim, your spouse has the right to respond to it, just as you've responded to her complaint or petition. Shortly after you serve it on her, she will probably file an "answer to counterclaim," asking the court to deny you the relief you asked for. Your spouse's answer to the counterclaim is the final word in most states -- you usually can't file an answer to her answer.
One of the greatest advantages to filing a counterclaim, as opposed to just an answer, is that it keeps your litigation alive if your spouse decides she doesn't want the divorce after all. If she withdraws or dismisses her complaint and you only filed an answer, your divorce legally ends. If you still want a divorce, you'll have to start all over again and file a petition or complaint of your own. However, if you filed a counterclaim, it's a lawsuit in and of itself. You're still suing your spouse for divorce, even if she is no longer suing you for one, so your divorce would proceed.