Interrogatories are a discovery tool (among many) used in lawsuits in New York courts. In sum, these are written questions seeking specific information.1. Except as otherwise provided herein, after commencement of an action, any party may serve upon any other party written interrogatories. Service of interrogatories. After commencement of an action, any party may serve written interrogatories upon any other party. In many civil actions, before the case is resolved there takes place a process known as pretrial discovery. This summary describes the process. Complete 10 days after the filing. A party may direct written interrogatories to any other party. A copy of the interrogatories shall be served on all other parties entitled to notice.