(a) Prerequisites to a class action. 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, and (4) the representative parties will fairly and adequately protect the interests of the class.
Rule 23.Class Actions.
Last amended July 1, 2011 · Last verified July 3, 2026
In one sentenceRule 23 sets the requirements for suing or being sued as a class, the three grounds on which a class action can be maintained, and how the court manages notice, judgment, dismissal, and any leftover settlement funds.
Full Text of Rule 23
(b) Class actions maintainable. An action may be maintained as a class action if the prerequisites of subdivision (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 final 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) Determination by order whether class action to be maintained; notice; judgment; actions conducted partially as 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 subdivision may be conditional, and may be altered or amended before the decision on the merits.
(2) In any class action maintained under subdivision (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 the member from the class if the member 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 the member desires, enter an appearance through counsel.
(3) The judgment in an action maintained as a class action under subdivision (b)(1) or (b)(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 (b)(3), whether or not favorable to the class, shall include and specify or describe those to whom the notice provided in subdivision (c)(2) 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 this rule shall then be construed and applied accordingly.
(d) Orders in conduct of actions. In the conduct of actions to which this rule 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 Rule 16, and may be altered or amended as may be desirable from time to time.
(e) Dismissal or compromise. 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.
(f) Distribution. Prior to the entry of any judgment under subdivision (c)(3) or the approval of any compromise under subdivision (e), the court shall determine the total amount payable to each class member. The court shall set a date when the parties shall report to the court the total amount actually paid to class members. After the report is received, the court shall direct the defendant, by order entered on the record, to distribute the sum of any unpaid residue after the payment of approved class member claims, expenses, litigation costs, attorneys’ fees, and other court-approved disbursements. Unless otherwise required by governing law, it shall be within the discretion of the court to approve the timing and method of distribution of residual funds and to approve the recipient(s) of residual funds, as agreed to by the parties, including nonprofit tax exempt organizations eligible to receive assistance from the indigent legal assistance fund under HRS section 607-5.7 (or any successor provision) or the Hawai‘i Justice Foundation, for distribution to one or more of such organizations.
Amendment History
Amended May 15, 1972, effective July 1, 1972
further amended December 7, 1999, effective January 1, 2000
further amended January 27, 2011, effective July 1, 2011
Plain-English Summary
Rule 23(a) requires four things before anyone can sue or be sued as a class representative: the class must be too numerous for individual joinder to be practical, the case must raise questions of law or fact common to the class, the representatives' claims or defenses must be typical of the class, and the representatives must be able to adequately protect the class's interests. Beyond those four prerequisites, Rule 23(b) requires at least one of three things to be true: separate lawsuits would risk inconsistent rulings or would as a practical matter decide the interests of class members not before the court; the party opposing the class acted on grounds that make class-wide injunctive or declaratory relief appropriate; or common questions predominate over individual ones and a class action is the superior way to resolve the dispute.
Once a case is filed as a class action, the court must decide as soon as practicable whether to let it proceed that way, and that decision can be revisited before judgment. Class members generally get the best notice practicable, including individual notice where feasible, and a chance to opt out; the judgment then binds those who didn't exclude themselves. The court can manage the case through orders addressing how evidence and argument proceed, what notice class members get, conditions on the representative parties, and similar procedural matters, and a class action can't be dismissed or settled without the court's approval and notice to the class. Where money is left over after paying approved claims, expenses, costs, and fees, Rule 23(f) lets the court direct distribution of the unpaid residue, including to eligible nonprofit organizations such as those supporting indigent legal assistance or the Hawai‘i Justice Foundation.
Frequently Asked Questions
What four things must be true before a class action can proceed under Rule 23(a)?
The class must be too numerous for individual joinder to be practical, there must be questions of law or fact common to the class, the representatives' claims or defenses must be typical of the class, and the representatives must be able to adequately protect the class's interests.
Can a class action be settled without the court's involvement?
No. Rule 23(e) requires court approval of any dismissal or compromise, and notice of the proposed dismissal or compromise must go to the class.
What happens to money left over after a class settlement is paid out?
Rule 23(f) lets the court direct distribution of any unpaid residue after approved claims, expenses, costs, and fees are paid, including to eligible nonprofit organizations the parties agree on.
Source & verification. The rule text and History are reproduced verbatim from the
official Hawaii Rules of Civil Procedure (Haw. R. Civ. P. 23). Prescribed by the Supreme Court of Hawaii (Haw. Rev. Stat. § 602-11; Haw. Const. art. VI, § 7). The plain-English summary is original and written by us. Last verified July 3, 2026. ·
Official source
Also known as: class action requirementsclass certificationclass action settlement