California Civil Procedure Code
Any party may obtain discovery by one or more of the following methods:
(a) Oral and written depositions.
(b) Interrogatories to a party.
(c) Inspections of documents, things, and places.
(d) Physical and mental examinations.
(e) Requests for admissions.
(f) Simultaneous exchanges of expert trial witness information.
(a) Except as otherwise provided by a rule of the Judicial Council, a local court rule, or a local uniform written policy, the methods of discovery may be used in any sequence, and the fact that a party is conducting discovery, whether by deposition or another method, shall not operate to delay the discovery of any other party.
(b) Notwithstanding subdivision (a), on motion and for good cause shown, the court may establish the sequence and timing of discovery for the convenience of parties and witnesses and in the interests of justice.
(a) The court shall restrict the frequency or extent of use of a discovery method provided in Section 2019.010 if it determines either of the following:
(1) The discovery sought is unreasonably cumulative or duplicative, or is obtainable from some other source that is more convenient, less burdensome, or less expensive.
(2) The selected method of discovery is unduly burdensome or expensive, taking into account the needs of the case, the amount in controversy, and the importance of the issues at stake in the litigation.
(b) The court may make these determinations pursuant to a motion for a protective order by a party or other affected person. This motion shall be accompanied by a meet and confer declaration under Section 2016.040.
(c) The court shall impose a monetary sanction under Chapter 7 (commencing with Section 2023.010) against any party, person, or attorney who unsuccessfully makes or opposes a motion for a protective order, unless it finds that the one subject to the sanction acted with substantial justification or that other circumstances make the imposition of the sanction unjust.