Part IV: Parties · Last amended 1985 · Last verified July 16, 2026
In one sentenceRule 15-6-23 sets the four prerequisites a class must meet to sue or be sued as a group, the three separate grounds that make a class action maintainable, and the court’s power to certify, notify, manage, and approve the dismissal or settlement of a class action.
(a)Prerequisites. One or more members of a class may sue or be sued as representative parties on behalf of all only if:
(1)the class is so numerous that joinder of all members is impracticable,
(2)there are questions of law or fact common to the class,
(3)the claims or defenses of the representative parties are typical of the claims or defenses of the class,
(4)the representative parties will fairly and adequately protect the interests of the class, and
(5)the suit is not against this state for the recovery of a tax imposed by chapter 10-39, 10-39A, 10-40, 10-41, 10-43, 10-44, 10-45, 10-46, 10-46A, 10-46B, or 10-52.
(b)What class actions are maintainable. An action may be maintained as a class action if the prerequisites of § 15-6-23(a) are satisfied, and in addition:
(1)the prosecution of separate actions by or against individual members of the class would create a risk of:
(A)inconsistent or varying adjudications with respect to individual members of the class which would establish incompatible standards of conduct for the party opposing the class; or
(B)adjudications with respect to individual members of the class which would as a practical matter be dispositive of the interests of the other members not parties to the adjudications or substantially impair or impede their ability to protect their interests; or
(2)the party opposing the class has acted or refused to act on grounds generally applicable to the class, thereby making appropriate permanent injunctive relief or corresponding declaratory relief with respect to the class as a whole; or
(3)the court finds that the questions of law or fact common to the members of the class predominate over any questions affecting only individual members, and that a class action is superior to other available methods for the fair and efficient adjudication of the controversy. The matters pertinent to the findings include:
(A)the interest of members of the class in individually controlling the prosecution or defense of separate actions;
(B)the extent and nature of any litigation concerning the controversy already commenced by or against members of the class;
(C)the desirability or undesirability of concentrating the litigation of the claims in the particular forum;
(D)the difficulties likely to be encountered in the management of a class action.
(c)Court’s determination as to maintainability of class action — Partial class actions.
(1)As soon as practicable after the commencement of an action brought as a class action, the court shall determine by order whether it is to be so maintained. An order under this section may be conditional, and may be altered or amended before the decision on the merits.
(2)In any class action maintained under subdivision 15-6-23(b)(3), the court shall direct to the members of the class the best notice practicable under the circumstances, including individual notice to all members who can be identified through reasonable effort. The notice shall advise each member that (A) the court will exclude him from the class if he so requests by a specified date; (B) the judgment, whether favorable or not, will include all members who do not request exclusion; and (C) any member who does not request exclusion may, if he desires, enter an appearance through his counsel.
(3)The judgment in an action maintained as a class action under subdivisions 15-6-23(b)(1) or (2), whether or not favorable to the class, shall include and describe those whom the court finds to be members of the class. The judgment in an action maintained as a class action under subdivision 15-6-23(b)(3), whether or not favorable to the class, shall include and specify or describe those to whom the notice provided in subdivision (2) of this section was directed, and who have not requested exclusion, and whom the court finds to be members of the class.
(4)When appropriate (A) an action may be brought or maintained as a class action with respect to particular issues, or (B) a class may be divided into subclasses and each subclass treated as a class, and the provisions of § 15-6-23 shall then be construed and applied accordingly.
(d)Orders in conduct of actions. In the conduct of actions to which § 15-6-23 applies, the court may make appropriate orders:
(1)Determining the course of proceedings or prescribing measures to prevent undue repetition or complication in the presentation of evidence or argument;
(2)Requiring, for the protection of the members of the class or otherwise for the fair conduct of the action, that notice be given in such manner as the court may direct to some or all of the members of any step in the action, or of the proposed extent of the judgment, or of the opportunity of members to signify whether they consider the representation fair and adequate, to intervene and present claims or defenses, or otherwise to come into the action;
(3)Imposing conditions on the representative parties or on intervenors;
(4)Requiring that the pleadings be amended to eliminate therefrom allegations as to representation of absent persons, and that the action proceed accordingly;
(5)Dealing with similar procedural matters.
The orders may be combined with an order under § 15-6-16, and may be altered or amended as may be desirable from time to time.
(e)Dismissal or compromise of class action. A class action shall not be dismissed or compromised without the approval of the court, and notice of the proposed dismissal or compromise shall be given to all members of the class in such manner as the court directs.
Plain-English Summary
Before anyone can sue or be sued on behalf of a class in South Dakota, subdivision (a) requires four things at once: the class must be so numerous that joining every member individually is impracticable; the case must raise questions of law or fact common to the class; the representative parties’ claims or defenses must be typical of the class; and those representatives must be able to protect the class’s interests adequately. A suit against the state to recover certain state taxes cannot proceed as a class action at all.
Meeting those four prerequisites is not enough on its own. Subdivision (b) requires one of three additional showings: that separate individual suits would risk inconsistent rulings that set incompatible standards for the opposing party, or would as a practical matter dispose of absent members’ interests; that the opposing party acted on grounds applying to the whole class, making class-wide injunctive or declaratory relief appropriate; or that common questions predominate over individual ones and a class action is the superior way to resolve the dispute, weighed against factors like members’ interest in controlling their own suits, existing related litigation, the desirability of this forum, and how manageable the class action would be.
Once a case is filed as a class action, the court must decide as soon as practicable whether it will proceed that way, and that determination can be conditional or later altered. Classes certified under the predominance-and-superiority ground get the best notice practicable, including individual notice to identifiable members, telling them they can opt out by a set date, that a judgment binds everyone who does not opt out, and that they may appear through their own counsel. A class action may also be certified on particular issues only, or split into subclasses.
The court retains ongoing authority to manage how the case proceeds — controlling the presentation of evidence, ordering notice to the class at various points, imposing conditions on representatives or intervenors, and requiring pleadings to be amended to drop allegations about absent members. A class action cannot be dismissed or settled without court approval, and notice of any proposed dismissal or settlement must go out to the class.
Frequently Asked Questions
What four things must be true before a group can sue as a class in South Dakota?
Under Rule 15-6-23(a), the class must be too numerous for practical joinder, share common questions of law or fact, have representatives with typical claims or defenses, and have representatives who can adequately protect the class’s interests.
Can a class action be used to recover a South Dakota state tax?
No. Rule 15-6-23(a)(5) excludes from class treatment any suit against the state for the recovery of a tax imposed under the listed tax chapters.
Do class members get notice and a chance to opt out of a South Dakota class action?
When the class is certified on predominance-and-superiority grounds under subdivision (b)(3), Rule 15-6-23(c)(2) requires the best notice practicable, telling members they may request exclusion by a specified date and that a judgment will otherwise include them.
Can a South Dakota class action be settled without the court’s approval?
No. Rule 15-6-23(e) requires court approval before a class action is dismissed or compromised, along with notice of the proposed dismissal or compromise to the class.
Can a South Dakota court certify a class action for only part of a case?
Yes. Rule 15-6-23(c)(4) allows an action to be brought or maintained as a class action on particular issues, or allows the class to be divided into subclasses, each treated as its own class.
Amendment History
(a)SDC 1939 & Supp 1960, § 33.0410; SD RCP, Rule 23 (a), as adopted by Sup. Ct. Order March 29, 1966, effective July 1, 1966; as amended by Sup. Ct. Order No. 2, March 31, 1969, effective July 1, 1969; SL 1982, ch 99, § 9; 1985, ch 15, § 31.
(b)SD RCP, Rule 23 (b), as adopted by Sup. Ct. Order No. 2, March 31, 1969, effective July 1, 1969; SL 1978, ch 155, § 1.
(c)SD RCP, Rule 23 (c), as adopted by Sup. Ct. Order No. 2, March 31, 1969, effective July 1, 1969.
(d)SD RCP, Rule 23 (d), as adopted by Sup. Ct. Order No. 2, March 31, 1969, effective July 1, 1969.
(e)SD RCP, Rule 23 (c), as adopted by Sup. Ct. Order March 29, 1966, effective July 1, 1966; SDCL, § 15-6-23(c); SD RCP, Rule 23 (e) as adopted by Sup. Ct. Order No. 2, March 31, 1969, effective July 1, 1969.
Source & verification. Rule text and History are
reproduced verbatim from the South Dakota Codified Laws, published by the
South Dakota Legislative Research Council. Last verified July 16, 2026.
· Official source
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