§ 2003 Commencement of action.

A civil case officially starts the moment someone files a petition with the court. The petition is the document that lays out what the person filing (the plaintiff) is asking for and why. Once this paperwork is filed, the lawsuit is considered to be underway.

This matters because filing dates can affect deadlines in a case, like statutes of limitations. If you file your petition before a legal deadline passes, your case counts as started on time, even if other steps (like notifying the other side) happen later.