Formal Discovery: Gathering Evidence for Your Lawsuit

Learn about formal discovery in a lawsuit using the most common discovery techniques.

By Paul Bergman , UCLA Law School Professor Updated 5/17/2024

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Discovery in law is a process used to seek information needed to prove claims in a lawsuit. Discovery begins soon after a lawsuit gets underway, with the parties to the lawsuit or their lawyers gathering needed information from the opposing side and potential witnesses. The process is called "discovery" because it often reveals facts and documents previously unknown to at least one party to the lawsuit.

Gathering Evidence Using Formal Discovery

Most discovery occurs outside the courtroom, with parties exchanging written information and sitting through face-to-face questioning sessions (called "depositions"). The types of evidence that can be legally obtained are very broad, including:

How to Do Discovery in a Lawsuit: Discovery Procedures

Four types of formal discovery tools are frequently used in lawsuits. The most common discovery techniques include:

Examples of Discovery in Law: What Can Be Discovered

The basic rule of discovery is that a party may obtain any information that pertains even slightly to any issue in the lawsuit as long as the information is not "privileged" or otherwise legally protected (see "Discovery Limits" below). Here are some of the things lawyers often ask for in discovery:

Limits on What Can Be Discovered

Virtually any information that might be slightly connected to the lawsuit is fair game for discovery. But this enormous latitude sometimes leads to abuse. Lawyers might try to pry into subjects with no legitimate significance for the lawsuit or are private and confidential, only to annoy or embarrass the parties. Fortunately, there are some legal limits on this kind of probing and some protections to keep private material from being disclosed to the public.

Confidential conversations. Conversations between people engaged in certain relationships are given a special legal protection known as privilege. Courts and legislatures have decided that the free flow of confidential information in these relationships is so important that it must be protected, even though that information might be important to others in a lawsuit. Under the law, no one can be required to disclose any information, whether verbal or written, that was confidentially exchanged within the following relationships:

Private matters. In recent years, courts have increasingly recognized that some aspects of personal life should remain private, beyond the reach even of lawyers. But the right to privacy is a fairly recent and still-developing legal notion. As a result, there is no clear definition of precisely what it covers -- and the extent of its protection varies considerably from state to state. Roughly, the right to privacy protects a person from having to divulge information that is not obviously relevant to the lawsuit and is a matter that a person would not normally discuss or reveal to anyone outside of immediate family and intimate friends. This might include issues such as:

Privacy rights of third parties. Courts are more willing to protect the privacy of third parties -- for example, witnesses, co-workers, or family members of a party -- than the privacy of parties to a lawsuit. Courts often limit how much a party can find out about someone who isn't involved in a lawsuit, reasoning that it isn't fair to invade the privacy of someone who was dragged into a dispute.

Keeping discovery information from the public. Even if a party is required to disclose certain information to the other side in a lawsuit, that information can be treated confidentially by the court -- that is, the party who receives it can be prevented from revealing it to anyone else, and the court can keep it out of the public record. This might be done to protect, for example, sensitive financial information, confidential information belonging to a business, or personal medication information that is relevant to the lawsuit. For this to happen, a judge must usually order that information be kept confidential, in what's often called a "protective order."

Want to Learn More?

These discovery tools are explained in detail in Represent Yourself in Court, by Paul Bergman and Sara Berman (Nolo), and Nolo's Deposition Handbook, by Paul Bergman and Albert Moore.