Rule 51.General Provisions Governing Discovery
Part VII. Disclosure and Discovery · Last amended January 1, 2026 · Last verified September 4, 2026
Full Text of Rule 51
Rule History
Added Aug. 30, 2018, effective Jan. 1, 2019. Amended effective Aug. 29, 2022; Jan. 24, 2025; Jan. 1, 2026.
Plain-English Summary
Rule 51 is the general discovery rule. It governs scope, limits, privilege and sequence for everything in Part VII.
Six methods
Depositions (Rule 57), interrogatories (Rule 60), requests for production and entry onto land (Rule 62), physical, mental and vocational examinations (Rule 63), requests for admission (Rule 64), and subpoenas for documents or premises (Rule 52).
Scope, and the proportionality test
Parties may discover any nonprivileged matter relevant to a claim or defense and proportional to the needs of the case, weighing the importance of the issues, the amount in controversy, relative access to information, the parties' resources, the importance of the discovery to resolving the issues, and whether burden or expense outweighs likely benefit. Information need not be admissible to be discoverable.
Then the sentence practitioners miss: written discovery to a party may not request information that party is already required to disclose under Rules 49 or 91 through 92. Complaints about the adequacy of disclosure go to Rule 65, not to a fresh set of interrogatories.
The court must limit discovery, on motion or its own, that is unreasonably cumulative or duplicative, obtainable from a more convenient or less expensive source, sought after ample opportunity to get it, or outside the permitted scope.
Work product
Materials prepared in anticipation of litigation are ordinarily not discoverable, but may be had on a showing of substantial need plus inability to obtain the substantial equivalent without undue hardship. Even then the court must protect the mental impressions, conclusions, opinions and legal theories of a party's attorney or representative. Separately, any party or person may obtain their own previous statement without any showing at all.
Experts
A disclosed expert may be deposed. A consulting expert not expected to testify is ordinarily off limits, reachable only through Rule 63(e) or on exceptional circumstances. The party seeking expert discovery must pay the expert a reasonable fee for responding, including deposition time.
Privilege, and clawback
Withheld material must be promptly identified in writing and described well enough for others to assess the claim without revealing the protected content. If privileged material is produced inadvertently, notice triggers four duties on the recipient: promptly return, sequester or destroy it and any copies; stop using or disclosing it; take reasonable steps to retrieve anything already passed on; and, if desired, present it to the court under seal. The producing party must preserve it until the claim is resolved.
Sequence, supplementation, sanctions
Methods may be used in any sequence, and one party's discovery does not require another to wait. A response that becomes materially incomplete or incorrect must be supplemented in a timely manner and in no event more than 30 days after the party learns of it. The court may sanction unreasonable, groundless, abusive or obstructionist conduct, and every discovery or disclosure motion must attach a Rule 9(c) good faith consultation certificate.
Frequently Asked Questions
Can I send interrogatories asking for the financial documents Rule 49 requires?
No. Rule 51(b)(1)(A) says written discovery to a party may not request information that party is required to disclose under Rules 49 or 91 through 92, and sends disputes about the adequacy of disclosure to Rule 65.
What is the standard for discoverable material?
Rule 51(b)(1)(A) allows discovery of any nonprivileged matter relevant to a claim or defense and proportional to the needs of the case, and says information need not be admissible in evidence to be discoverable.
Can I get my own prior statement without a court fight?
Yes. Rule 51(b)(3)(C) lets any party or person obtain their own previous statement about the action without the substantial-need showing that other work product requires.
What happens if privileged documents are produced by mistake?
Rule 51(b)(5)(B) requires the receiving party, once notified, to promptly return, sequester or destroy the material and any copies, stop using or disclosing it, take reasonable steps to retrieve it if already disclosed, and allows presenting it to the court under seal. The producing party must preserve it until the claim is resolved.
Do I have to pay the other side's expert to sit for a deposition?
Rule 51(b)(4)(C) requires the party seeking the discovery to pay the expert a reasonable fee for time spent responding, including deposition testimony, unless manifest injustice would result.
Does every discovery motion need a consultation certificate?
Yes. Rule 51(f) requires any discovery or disclosure motion to attach a good faith consultation certificate complying with Rule 9(c).