California discovery rules live in the Code of Civil Procedure and give every party in a civil lawsuit broad authority to gather evidence before trial, through written questions, document demands, depositions, and physical or mental exams, all running on deadlines tied to the trial date. The rules are generous in scope and strict on timing. Miss a response window and you can waive your objections; miss the motion window and you lose your right to challenge a bad answer; miss the discovery cutoff and you may be done gathering evidence altogether, even if the trial gets continued.
What You Can Ask For
Under CCP 2017.010, you can seek any non-privileged matter that is relevant to the subject of the lawsuit or to any pending motion. The information doesn’t have to be admissible at trial on its own. If a request could reasonably lead to admissible evidence, it falls within scope. That covers documents, electronically stored information, physical items, and the identities and locations of people who know something useful.1California Legislative Information. California Code CCP – Section 2017.010
Broad is not unlimited. Judges apply a proportionality standard, weighing the value of the information against the cost, burden, and privacy intrusion of producing it.2Justia. Williams v. Superior Court of Los Angeles County (2017) Discovery aimed at pressuring an opponent, or that pushes burden onto people who aren’t even parties, draws scrutiny from the court.
The Trial-Date Clock
Every discovery tool in a California civil case runs on a clock tied to the trial date. CCP 2024.020 sets two cutoffs: all discovery must be completed no later than 30 days before the date initially set for trial, and discovery motions must be heard at least 15 days before that trial date.3California Legislative Information. California Code CCP – Section 2024.020
The word “initially” matters. A trial continuance does not automatically reopen the discovery window. If the cutoff ran on the first scheduled trial date, you need an order under CCP 2024.050 reopening discovery before you can send more requests or notice more depositions. Litigants assume a new trial date resets everything. It doesn’t.
Initial Disclosures Since 2024
For cases filed on or after January 1, 2024, CCP 2016.090 allows any party to demand that all parties simultaneously exchange baseline information about the case. Each party then has 60 days to respond.4California Legislative Information. California Code CCP – Section 2016.090
The disclosure must identify witnesses with discoverable information the party may use to support its claims or defenses, including names, addresses, phone numbers, email addresses, and the subjects of their knowledge. It must also provide copies or a categorical description of documents, electronically stored information, and physical items in the party’s possession that may support its claims or defenses. And it must disclose any insurance or indemnity agreement under which someone may be liable to satisfy a judgment, including coverage limits and any dispute over coverage.
Two limits are worth knowing. Expert trial witnesses are not covered by initial disclosures; they travel through a separate exchange process. And parties who are not represented by an attorney are exempt from the requirement entirely. Parties can also modify these obligations by stipulation.
Written Discovery Tools
Written discovery does most of the day-to-day work in a California case. It is cheaper than depositions and locks down the other side’s positions in writing. Three methods carry the load.
Interrogatories
Interrogatories are written questions answered under oath. California offers two kinds. Form interrogatories use question sets approved by the Judicial Council, and you can serve as many of them as are relevant. Special interrogatories let you ask case-specific questions, but you are capped at 35 unless you serve a declaration showing why more are needed.5Justia. California Code CCP – Sections 2030.010 Through 2030.090
Responses are due within 30 days of personal service, or 35 days if mailed from within California.6Judicial Branch of California. Respond to a Request for Discovery in a Court Case Blow past that deadline and you waive every objection, including privilege, relevance, and burden.7Judicial Branch of California. Serve Your Response to a Request for Discovery
Supplemental interrogatories can be used to get updated information after the first round of answers. CCP 2030.070 lets you send them twice before the initial trial date is set and once afterward without needing court permission.8California Legislative Information. California Code CCP – Section 2030.070
Requests for Admission
Requests for admission ask the other side to admit or deny specific facts, the authenticity of documents, or the application of law to facts. The point is to narrow the real dispute so neither side wastes trial time proving things no one contests.
The response deadline matches interrogatories: 30 days from personal service, 35 if mailed within California. The consequences for silence are the harshest in California discovery. If a party fails to respond on time, the requesting party can move for an order deeming every matter admitted, and the court must grant that order unless a compliant response is served before the hearing. The court must also impose monetary sanctions on the party or attorney whose failure forced the motion.9California Legislative Information. California Code CCP – Section 2033.280 Once admitted, those facts are conclusive at trial.
Requests for Production
Requests for production compel the other party to turn over documents, electronically stored information, or physical items for inspection and copying. Each category must be described with enough specificity that the responding party knows what to look for. Responses are due within 30 days of personal service, and objections must be specific and supported by a stated reason.
If the responding party withholds a document on privilege or work product grounds, that is not the end of the matter. They must provide enough information for the requesting party to evaluate the claim. In practice this means a privilege log identifying the document, author, date, recipients, and the specific basis for withholding it.
Depositions
Depositions are sworn questioning of witnesses before trial, recorded for use at trial to impeach a witness who changes their testimony or to present testimony from someone who can’t appear. The procedures run from CCP 2025.010 through 2025.620.
To take a deposition, the noticing party serves a written notice stating the date, time, location, and whether the testimony will be captured by audio, video, or stenography. A non-party witness has to be subpoenaed.
Location rules trip people up. Under CCP 2025.250, a natural person’s deposition must be taken within 75 miles of the deponent’s residence, or within the county where the action is pending and within 150 miles of the deponent’s residence. For organizations that are parties, the reference point is the organization’s principal office in California. Non-party organizations get a tighter limit: 75 miles from their principal office, unless they agree to travel farther.10California Legislative Information. California Code CCP – Section 2025.250
Objections during a deposition are limited. Privilege, form of the question, and harassment are the usual grounds. An attorney may instruct a witness not to answer only to protect a privilege or a privacy right. Speaking objections designed to coach the witness and other obstructive tactics can draw sanctions.
Physical and Mental Examinations
When a party’s physical or mental condition is directly at issue, another party can obtain a court-ordered examination under CCP 2032.020. These come up in personal injury cases, employment cases alleging emotional distress, and custody matters.
Only certain people are examinable: a party, an agent of a party, or someone in the custody or legal control of a party. Physical exams must be performed by a licensed physician or appropriate health care practitioner. Mental exams require a licensed physician or a clinical psychologist with a doctoral degree and at least five years of postgraduate experience diagnosing emotional and mental disorders.11California Legislative Information. California Code CCP – Section 2032.020
Unlike written discovery, you generally cannot demand an exam unilaterally. If the parties can’t agree, you have to file a motion showing good cause. The order will set the time, place, scope, and conditions.
Expert Witness Exchange
California handles expert discovery through a simultaneous exchange rather than the sequential federal model. Under CCP 2034.210, once the trial date is set, any party can demand that all parties exchange expert trial witness lists, expert declarations, and any expert reports at the same time.12California Legislative Information. California Code CCP – Section 2034.210
Timing is strict. The demand must be served no later than the 10th day after the initial trial date is set, or 70 days before trial, whichever is closer to trial. The actual exchange occurs 50 days before the initial trial date, or 20 days after the demand is served, whichever is closer to trial.13Justia. California Code CCP – Sections 2034.210 Through 2034.310
For retained experts and party-employee experts, the exchange must include a declaration covering the expert’s qualifications, the general substance of the expected testimony, and the hourly and daily fee for deposition testimony. An expert not timely designated can be barred from testifying at trial.
Electronic Discovery
Electronic discovery runs on the same framework as paper production, with some added mechanics. Emails, text messages, databases, social media content, metadata, and deleted files are all within scope as electronically stored information.
If a responding party shows that requested ESI comes from a source that is not reasonably accessible because of undue burden or expense, such as backup tapes or legacy systems, the burden shifts to the requesting party to show good cause for production. Even with good cause shown, the court can allocate retrieval costs and set conditions on how the production proceeds.14California Legislative Information. California Code CCP – Section 2031.060
Preservation has a limited safe harbor. Under CCP 2023.030(f), courts generally cannot sanction a party for ESI lost through the routine, good-faith operation of an electronic system, absent exceptional circumstances. The statute is explicit that this does not eliminate the duty to preserve once litigation is anticipated. If you know a lawsuit is coming and fail to suspend automatic deletion, the safe harbor doesn’t help.15California Legislative Information. California Code CCP – Section 2023.030
When the Other Side Won’t Cooperate
California splits motions to compel into two distinct situations, and treating them the same is a common mistake.
If the other party never responded at all, you can file a motion to compel initial responses any time before the discovery motion cutoff. There is no meet-and-confer requirement for this version, because there is nothing to discuss. For interrogatories, the authority sits at CCP 2030.290; for document requests, CCP 2031.310.
If the other party did respond but the answers are evasive, incomplete, or lean on boilerplate objections, you have 45 days from receipt of the verified response to file a motion to compel further responses. Miss that window and the right to challenge those answers is gone for good.16California Legislative Information. California Code CCP – Section 2030.300
Any motion to compel further responses has to be preceded by a good-faith meet-and-confer effort under CCP 2016.040, usually a letter or call explaining what’s deficient and what you want. The motion papers must include a declaration describing those efforts. Courts routinely deny motions where the declaration shows only token outreach.17California Legislative Information. California Code CCP – Section 2016.040
Protective Orders
A party facing a request that is oppressive, overbroad, or aimed at confidential information can move for a protective order under CCP 2031.060. The court can shape relief in several ways: trimming categories out of a request, extending the response deadline, moving the location for an inspection, requiring production under specified conditions, or sealing documents so they can only be opened by court order.14California Legislative Information. California Code CCP – Section 2031.060 Trade secret information is routinely handled through orders that let opposing counsel view the material under strict confidentiality while barring them from sharing it with clients or using it outside the case.18Justia. Bridgestone/Firestone, Inc. v. Superior Court (Rios) (1992)
Protective order motions carry the same meet-and-confer requirement as motions to compel. The moving party bears the burden of showing good cause.
Sanctions for Discovery Abuse
Judges enforce the rules through a graduated set of sanctions under CCP 2023.030. Monetary sanctions order the offending party, their attorney, or both to pay the other side’s reasonable expenses, including attorney fees, caused by the misconduct; when a discovery statute authorizes monetary sanctions, the court must impose them unless the offending party acted with substantial justification or the sanction would be unjust. Issue sanctions treat designated facts as established against the offending party or bar them from supporting or opposing specific claims. Evidence sanctions prohibit introducing designated evidence at trial. Terminating sanctions strike the party’s pleadings, dismiss the action, or enter default judgment. Contempt sanctions treat the misconduct as contempt of court.15California Legislative Information. California Code CCP – Section 2023.030
Courts generally impose sanctions in ascending order, starting with monetary penalties and escalating only after lesser measures fail to produce compliance. Case-ending sanctions are rare, but they do happen when a party treats discovery obligations as optional.19Justia. R.S. Creative, Inc. v. Creative Cotton, Ltd. (1999)