N.J. Ct. R. 4:32-1

(a) General 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.

(b) Class Actions Maintainable. An action may be maintained as a class action if the prerequisites of paragraph (a) are satisfied, and in addition:

(1) the prosecution of separate actions by or against individual members of the class would create a risk either of:

(a) inconsistent or varying adjudications with respect to individual members of the class that would establish incompatible standards of conduct for the party opposing the class, or

(b) adjudications with respect to individual members of the class that 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 factors 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 in concentrating the litigation of the claims in the particular forum; and

(d) the difficulties likely to be encountered in the management of a class action.