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 Pennsylvania, the discovery process in civil litigation is governed by the Pennsylvania Rules of Civil Procedure. These rules outline the methods and scope of discovery, including the exchange of documents, answering of interrogatories, and the taking of depositions. Parties may request the production of documents, submit written questions to be answered under oath, and depose witnesses. Additionally, there are provisions for making disclosures without a request from the opposing party and for issuing subpoenas to third parties for documents or depositions. The discovery process is crucial for parties to gather evidence and prepare for trial. It can be extensive and costly, and it is subject to deadlines and limitations to ensure relevance and protect privileged information. Attorneys play a key role in managing the discovery process, ensuring compliance with the rules, and protecting their clients' interests.