Section 15-6-23(b) - Class actions maintainableAn 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.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.