Civil procedure: Federal Rules of Civil Procedure: Pre-trial procedure: Interrogatories + Deposition (Part One)

In law, interrogatories (also known as requests for further information) are a formal set of written questions propounded by one litigant and required to be answered by an adversary in order to clarify matters of fact and help to determine in advance what facts will be presented at any trial in the case.

Use.

Interrogatories are used to gain information from the other party relevant to the issues in a lawsuit. The law and issues will differ depending upon the facts of a case and the laws of the jurisdiction in which a lawsuit is filed. For some types of cases there are standard sets of interrogatories available that cover the essential facts, and may be modified for the case in which they are used.

When a lawsuit is filed, the pleadings filed by the parties are intended to let the other parties know what each side intends to prove at trial, and what legal case they have to answer. However, in most cases, the parties will require additional information to fully understand each other's legal and factual claims. The discovery process, including the use of interrogatories, can help the parties obtain that information from each other.

For an example of how interrogatories may be used, in a motor vehicle accident lawsuit, an injured plaintiff typically asserts that the defendant driver committed the tort of negligence in causing the accident. To prove negligence, the law requires the injured plaintiff to show that the driver owed them a duty of care and breached it, causing the injury. Assuming that the defendant did not dispute driving a vehicle that was involved in the accident that injured the plaintiff, the case would come down to whether the driver drove in accordance with the standard of a reasonable driver, and whether the injured person's injuries are a foreseeable consequence of the driving.

The parties may use interrogatories to seek information, including concessions as to how the accident occurred, from each other. The injured plaintiff might serve interrogatories on the defendant driver seeking information that would support the plaintiff's theory of the case. If the plaintiff is alleging that the defendant was speeding, the plaintiff might ask the defendant to state the speed of the defendant's vehicle at the time of the accident. If the plaintiff alleges that the defendant failed to control the car properly or failed to pay proper attention to the road and other vehicles, the plaintiff could ask interrogatory questions that would help prove those allegations or require disclosure of the basis of any denial of negligence by the defendant. The driver may have a defense to those allegations, perhaps if the accident occurred at low speed, and was unavoidable (maybe due to some third party intervention). The injured person may, however, argue that the driver was still responsible (perhaps the driver should have used the horn of the vehicle to alert the third party), or there may be other allegations.

The defense may similarly use interrogatories to help build legal and factual defenses to the plaintiff's case. Continuing with the example of a car accident, the defendant may seek information or concessions from the plaintiff that would suggest that a different driver was partially or wholly responsible for the accident, or that under the facts the accident was unavoidable despite the proper exercise of care.