Discovery is the factfinding process in civil litigation in which the parties to a lawsuit exchange requests for the production of documents and other tangible items (requests for production); written questions to be answered under oath (interrogatories); witness testimony to be provided by oral deposition; disclosures that may be required under the applicable rules without request from an opposing party; and requests or subpoenas to third-parties (who are not parties to the lawsuit) for the production of documents or tangible things, or the giving of testimony by oral deposition, for example.

The discovery process is one of the most important, time-consuming, and often expensive parts of civil litigation. The discovery process—including the scope of discovery requests, deadlines to respond, and privileges from responding—are usually governed by the state or jurisdiction’s rules of civil procedure or code of civil procedure. For example, in federal court discovery is governed by the Federal Rules of Civil Procedure.

In Massachusetts, the discovery process in civil litigation is governed by the Massachusetts Rules of Civil Procedure, which closely mirror the Federal Rules of Civil Procedure. During discovery, parties may request the production of documents, submit interrogatories, take depositions, and make other disclosures as required by the rules. The scope of discovery is generally broad, allowing parties to obtain any non-privileged material that is relevant to any party's claim or defense and proportional to the needs of the case. Deadlines for responding to discovery requests are set by the rules and by court orders. Certain materials may be protected from disclosure by privileges, such as attorney-client privilege or work product doctrine. The discovery process is designed to narrow the issues for trial, eliminate surprise, and achieve substantial justice. It is crucial for parties to adhere to the rules and deadlines to avoid sanctions and ensure a fair legal process.