(c) PROCEDURE. A person desiring to intervene shall serve a motion to intervene upon the parties as provided in Rule 5. The motion shall state the grounds therefor and shall be accompanied by a pleading setting forth the claim or defense for which intervention is sought. The same procedure shall be followed when a statute of the United States gives a right to intervene. When the constitutionality of an act of Congress affecting the public interest is drawn in question in any action to which the United States or an officer, agency, or employee thereof is not a party, the court shall notify the Attorney General of the United States as provided in Title 28, U.S.C., § 2403. (As amended Dec. 27, 1946, eff. Mar. 19, 1948; Dec. 29, 1948, eff. Oct. 20, 1949; Jan. 21, 1963, eff. July 1, 1963; Feb. 28, 1966, eff. July 1, 1966.)

Rule 25. Substitution of Parties.

(a) DEATH.

(1) If a party dies and the claim is not thereby extinguished, the court may order substitution of the proper parties. The motion for substitution may be made by any party or by the successors or representatives of the deceased party and, together with the notice of hearing, shall be served on the parties as provided in Rule 5 and upon persons not parties in the manner provided in Rule 4 for the service of a summons, and may be served in any judicial district. Unless the motion for substitution is made not later than 90 days after the death is suggested upon the record by service of a statement of the fact of the death as provided herein for the service of the motion, the action shall be dismissed as to the deceased party.

(2) In the event of the death of one or more of the plaintiffs or of one or more of the defendants in an action in which the right sought to be enforced survives only to the surviving plaintiffs or only against the surviving defendants, the action does not abate. The death shall be suggested upon the record and the action shall proceed in favor of or against the surviving parties. (b) INCOMPETENCY. If a party becomes incompetent, the court upon motion served as provided in subdivision (a) of this rule may allow the action to be continued by or against his representative.

(c) TRANSFER OF INTEREST. In case of any transfer of interest, the action may be continued by or against the original party, unless the court upon motion directs the person to whom the interest is transferred to be substituted in the action or joined with the original party. Service of the motion shall be made as provided in subdivision (a) of this rule.

(d) PUBLIC OFFICERS; DEATH OR SEPARATION FROM OFFICE.

(1) When a public officer is a party to an action in his official capacity and during its pendency dies, resigns, or otherwise ceases to hold office, the action does not abate and his successor is automatically substituted as a party. Proceedings following the substitution shall be in the name of the substituted party, but any misnomer not affecting the substantial rights of the parties shall be disregarded. An order of substitution may be entered at any time, but the omission to enter such an order shall not affect the substitution.

(2) When a public officer sues or is sued in his official capacity, he may be described as a party by his official title rather than by name; but the court may require his name to be added.

(As amended Dec. 29, 1948, eff. Oct. 20, 1949; Apr. 17, 1961, eff. July 19, 1961; Jan. 21, 1963, eff. July 1, 1963.)

TITLE V. DEPOSITIONS AND DISCOVERY

Rule 26. General Provisions Governing Discovery.

(a) DISCOVERY METHODS. Parties may obtain discovery by one or more of the following methods: depositions upon oral examination or written questions; written interrogatories; production of documents or things or permission to enter upon land or other property, for inspection and other purposes; physical and mental examinations; and requests for admission. Unless the court orders otherwise under subdivision (c) of this rule, the frequency of use of these methods is not limited.

(b) SCOPE OF DISCOVERY. Unless otherwise limited by order of the court in accordance with these rules, the scope of discovery is as follows:

(1) In General. Parties may obtain discovery regarding any matter, not privileged, which is relevant to the subject matter involved in the pending action, whether it relates to the claim or defense of the party seeking discovery or to the claim or defense of any other party, including the existence, description, nature, custody, condition and location of any books, documents, or other tangible things and the identity and location of persons having knowledge of any discoverable matter. It is not ground for objection that the information sought will be inadmissible at the trial if the information sought appears reasonably calculated to lead to the discovery of admissible evidence.

(2) Insurance Agreements. A party may obtain discovery of the existence and contents of any insurance agreement under which any person carrying on an insurance business may be liable to satisfy part or all of a judgment which may be entered in the action or to indemnify or reimburse for payments made to satisfy the judgment. Information concerning the insurance agreement is not by reason of disclosure admissible in evidence at trial. For purposes of this paragraph, an application for insurance shall not be treated as part of an insurance agreement.

(3) Trial Preparation: Materials. Subject to the provisions of subdivision (b)(4) of this rule, a party may obtain discovery of documents and tangible things otherwise discoverable under subdivision (b)(1) of this rule and prepared in anticipation of litigation or for trial by or for another party or by or for that other party's representative (including his attorney, consultant, surety, indemnitor, insurer, or agent) only upon a showing that the party seeking discovery has substantial need of the materials in the preparation of his case and that he is unable without undue hardship to obtain the substantial equivalent of the materials by other means. In ordering discovery of such materials when the required showing has been made, the court shall protect against disclosure of the mental impressions, conclusions, opinions, or legal theories of an attorney or other representative of a party concerning the litigation. A party may obtain without the required showing a statement concerning the action or its subject matter

previously made by that party. Upon request, a person not a party may obtain without the required showing a statement concerning the action or its subject matter previously made by that person. If the request is refused, the person may move for a court order. The provisions of Rule 37(a)(4) apply to the award of expenses incurred in relation to the motion. For purposes of this paragraph, a statement previously made is (A) a written statement signed or otherwise adopted or approved by the person making it, or (B) a stenographic, mechanical, electrical, or other recording, or a transcription thereof which is a substantially verbatim recital of an oral statement by the person making it and contemporaneously recorded.

(4) Trial Preparation: Experts. Discovery of facts known and opinions held by experts, otherwise discoverable under the provisions of subdivision (b)(1) of this rule and acquired or developed in anticipation of litigation or for trial, may be obtained only as follows:

(A) (i) A party may through interrogatories require any other party to identify each person whom the other party expects to call as an expert witness at trial, to state the subject matter on which the expert is expected to testify, and to state the substance of the facts and opinions to which the expert is expected to testify and a summary of the grounds for each opinion. (ii) Upon motion, the court may order further discovery by other means, subject to such restrictions as to scope and such provisions, pursuant to subdivision (b) (4) (C) of this rule, concerning fees and expenses as the court may deem appropriate.

(B) A party may discover facts known or opinions held by an expert who has been retained or specially employed by another party in anticipation of litigation or preparation for trial and who is not expected to be called as a witness at trial, only as provided in Rule 35(b) or upon a showing of exceptional circumstances under which it is impracticable for the party seeking discovery to obtain facts or opinions on the same subject by other means.

(C) Unless manifest injustice would result, (i) the court shall require that the party seeking discovery pay the expert a reasonable fee for time spent in responding to discovery under subdivisions (b)(4) (A)(ii) and (b)(4) (B) of this rule; and (ii) with respect to discovery obtained under subdivision (b)(4)(A)(ii) of this rule the court may require, and with respect to discovery obtained under subdivision (b) (4) (B) of this rule the court shall require, the party seeking discovery to pay the other party a fair portion of the fees and expenses reasonably incurred by the latter party in obtaining facts and opinions from the expert.

(c) PROTECTIVE ORDERS. Upon motion by a party or by the person from whom discovery is sought, and for good cause shown, the court in which the action is pending or alternatively, on matters relating to a deposition, the court in the district where the deposition is to be taken may make any order which justice requires to protect a party or person from annoyance, embarrassment, oppression, or undue burden or expense, including one or more of the following: (1) that the

discovery not be had; (2) that the discovery may be had only on specified terms and conditions, including a designation of the time or place; (3) that the discovery may be had only by a method of discovery other than that selected by the party seeking discovery; (4) that certain matters not be inquired into, or that the scope of the discovery be limited to certain matters; (5) that discovery be conducted with no one present except persons designated by the court; (6) that a deposition after being sealed be opened only by order of the court; (7) that a trade secret or other confidential research, development, or commercial information not be disclosed or be disclosed only in a designated way; (8) that the parties simultaneously file specified documents or information enclosed in sealed envelopes to be opened as directed by the court. If the motion for a protective order is denied in whole or in part, the court may, on such terms and conditions as are just, order that any party or person provide or permit discovery. The provisions of Rule 37(a) (4) apply to the award of expenses incurred in relation to the motion.

(d) SEQUENCE AND TIMING OF DISCOVERY. Unless the court upon motion, for the convenience of parties and witnesses and in the interests of justice, orders otherwise, methods of discovery may be used in any sequence and the fact that a party is conducting discovery, whether by deposition or otherwise, shall not operate to delay any other party's discovery.

(e) SUPPLEMENTATION OF RESPONSES. A party who has responded to a request for discovery with a response that was complete when made is under no duty to supplement his response to include information thereafter acquired, except as follows:

(1) A party is under a duty seasonably to supplement his response with respect to any question directly addressed to (A) the identity and location of persons having knowledge of discoverable matters, and (B) the identity of each person expected to be called as an expert witness at trial, the subject matter on which he is expected to testify, and the substance of his testimony.

(2) A party is under a duty seasonably to amend a prior response if he obtains information upon the basis of which (A) he knows that the response was incorrect when made, or (B) he knows that the response though correct when made is no longer true and the circumstances are such that a failure to amend the response is in substance a knowing concealment.

(3) A duty to supplement responses may be imposed by order of the court, agreement of the parties, or at any time prior to trial through new requests for supplementation of prior responses. (As amended Dec. 27, 1946, eff. Mar. 19, 1948; Jan. 21, 1963, eff. July 1, 1963; Feb. 28, 1966, eff. July 1, 1966; Mar. 30, 1970, eff. July 1, 1970.)

Rule 27. Depositions Before Action or Pending Appeal. (a) BEFORE ACTION.

(1) Petition. A person who desires to perpetuate his own testimony or that of another person regarding any matter that may be cognizable in any court of the United States may file a verified petition in the United States district court in the district of the residence of any expected adverse party. The petition shall be entitled in the name of the petitioner and shall show: 1, that the petitioner expects to be a party to an action cognizable

in a court of the United States but is presently unable to bring it or cause it to be brought, 2, the subject matter of the expected action and his interest therein, 3, the facts which he desires to establish by the proposed testimony and his reasons for desiring to perpetuate it, 4, the names or a description of the persons he expects will be adverse parties and their addresses so far as known, and 5, the names and addresses of the persons to be examined and the substance of the testimony which he expects to elicit from each, and shall ask for an order authorizing the petitioner to take the depositions of the persons to be examined named in the petition, for the purpose of perpetuating their testimony.

(2) Notice and Service. The petitioner shall thereafter serve a notice upon each person named in the petition as an expected adverse party, together with a copy of the petition, stating that the petitioner will apply to the court, at a time and place named therein, for the order described in the petition. At least 20 days before the date of hearing the notice shall be served either within or without the district or state in the manner provided in Rule 4(d) for service of summons; but if such service cannot with due diligence be made upon any expected adverse party named in the petition, the court may make such order as is just for service by publication or otherwise, and shall appoint, for persons not served in the manner provided in Rule 4(d), an attorney who shall represent them, and, in case they are not otherwise represented, shall cross-examine the deponent. If any expected adverse party is a minor or incompetent the provisions of Rule 17(c) apply.

(3) Order and Examination. If the court is satisfied that the perpetuation of the testimony may prevent a failure or delay of justice, it shall make an order designating or describing the persons whose depositions may be taken and specifying the subject matter of the examination and whether the depositions shall be taken upon oral examination or written interrogatories. The depositions may then be taken in accordance with these rules; and the court may make orders of the character provided for by Rules 34 and 35. For the purpose of applying these rules to depositions for perpetuating testimony, each reference therein to the court in which the action is pending shall be deemed to refer to the court in which the petition for such deposition was filed.

(4) Use of Deposition. If a deposition to perpetuate testimony is taken under these rules or if, although not so taken, it would be admissible in evidence in the courts of the state in which it is taken, it may be used in any action involving the same subject matter subsequently brought in a United States district court, in accordance with the provisions of Rule 26(d).

(b) PENDING APPEAL. If an appeal has been taken from a judgment of a district court or before the taking of an appeal if the time therefor has not expired, the district court in which the judgment was rendered may allow the taking of the depositions of witnesses to perpetuate their testimony for use in the event of further proceedings in the district court. In such case the party who desires to perpetuate the testimony may make a motion in the district court for leave to take the depositions, upon the same notice and service thereof as if