(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 subsection (c) of this Code section, 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 this chapter, 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 paragraph (4) of this subsection, a party may obtain discovery of documents and tangible things otherwise discoverable under paragraph (1) of this subsection 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. Paragraph (4) of subsection (a) of Code Section 9-11-37 applies 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; and

(4) Trial preparation; experts. Discovery of facts known and opinions held by experts, otherwise discoverable under paragraph (1) of this subsection 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) A party may obtain discovery under Code Section 9-11-30, 9-11-31, or 9-11-34 from any expert described in this paragraph, the same as any other witness, but the party obtaining discovery of an expert hereunder must pay a reasonable fee for the time spent in responding to discovery by that expert, subject to the right of the expert or any party to obtain a determination by the court as to the reasonableness of the fee so incurred;

(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 subsection (b) of Code Section 9-11-35 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; and

(C) Unless manifest injustice would result:

(i) The court shall require the party seeking discovery to pay the expert a reasonable fee for time spent in responding to discovery under subparagraph (B) of this paragraph; and

(ii) With respect to discovery obtained under division (ii) of subparagraph (A) of this paragraph, the court may require, and with respect to discovery obtained under subparagraph (B) of this paragraph 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 county 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; or

(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. Paragraph (4) of subsection (a) of Code Section 9-11-37 applies 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.