In law, discovery is the pre-trial phase in a lawsuit in which each party through the law of civil procedure can request documents and other evidence from other parties or can compel the production of evidence by using a subpoena or through other discovery devices, such as requests for production and depositions. In American law, discovery is wide-ranging and can involve any material which is relevant to the case excepting information which is privileged or information which is the work product of the lawyers other side.

In practice, most civil cases in the United States are settled after discovery. After discovery, both sides usually are in agreement about the strength of each side's case and this produces a settlement which eliminates the expense and risks of a trial. The use of discovery has been criticized as favoring the wealthier side as one tactic is to make requests of information which are expensive and time consuming for the other side to fulfil.