What is discovery in law?

Where it fits in a lawsuit

After the complaint and answer are filed, the court usually holds a scheduling conference and sets deadlines. Discovery then runs for months, sometimes more than a year in complex cases, and ends before motions for summary judgment and trial. In federal court and many states, parties must first make initial disclosures without being asked: names of witnesses, copies or descriptions of key documents, a computation of damages and any insurance policies.

The main tools

• Interrogatories — written questions answered in writing under oath; federal practice limits them to 25 per party without permission.
• Requests for production — documents, contracts, emails, text messages, social media posts, records and other electronically stored information.
• Depositions — live sworn questioning, transcribed and often video-recorded.
• Requests for admission — asking the other side to admit specific facts or the authenticity of documents, narrowing what has to be proved. Failing to respond on time can mean the facts are treated as admitted.
• Physical or mental examinations — available where a party's condition is genuinely in dispute, as in most injury cases.
• Subpoenas to non-parties for documents or testimony, such as medical providers, banks or phone companies.

The scope, and its limits

Federal Rule 26 allows discovery of any non-privileged matter relevant to a claim or defense and proportional to the needs of the case. Proportionality — the amount at stake, the importance of the issues, the parties' resources and the burden of the request — is what courts use to cut back sprawling electronic demands. Privileged material, such as attorney-client communications and attorney work product, is withheld but must be listed on a privilege log. Courts can also issue protective orders to keep trade secrets or personal information confidential.

The duty to preserve

Once litigation is reasonably anticipated, both sides must stop routine deletion and preserve relevant material — emails, texts, messaging apps, video, documents. A litigation hold notice is the standard mechanism for businesses. Destroying evidence after that point is spoliation, and sanctions range from an instruction that the jury may assume the lost evidence was harmful, to dismissal or default judgment. Individuals should not delete social media posts or messages about the dispute once a claim is in view.

Disputes about discovery

Parties must first try to resolve disagreements by conferring in good faith. If that fails, a party can file a motion to compel answers or production, and the court can order the losing side to pay the other's costs of the motion. Discovery fights are a major part of litigation expense, which is one reason most cases settle.

What discovery costs

In simple cases, discovery may involve a few hundred pages and a handful of depositions. In business cases with years of emails, electronic discovery can cost more than any other stage of the case. Each side generally pays its own costs of responding, although courts can shift costs for especially burdensome requests.

Criminal cases are different

Criminal discovery is much narrower and largely one-directional. The prosecution must disclose evidence favorable to the defense under Brady v. Maryland and impeachment material under Giglio, and statutory rules cover the defendant's statements, test results and reports. There is no general right to depose prosecution witnesses in most jurisdictions, and defendants cannot be compelled to give testimony.

Practical tips for parties

Gather and organize your documents early, tell your lawyer about anything harmful rather than hiding it, answer written discovery accurately and on time, and never alter or delete evidence. Honest, complete discovery responses protect your credibility with the court.

Discovery in small claims and arbitration

Small claims courts generally allow little or no formal discovery; each side simply brings its evidence to the hearing. In arbitration, discovery is usually narrower than in court and controlled by the arbitrator, often limited to exchanging key documents and a few depositions. That is one of arbitration's main cost savings, and one of its main drawbacks for a party whose proof is in the other side's files.