A dozen years ago, I wrote about California's single subject rule governing legislation - "A statute shall embrace but one subject, which shall be expressed in its title".  Cal. Const. Art. IV, § 9.  A similar rule applies to initiatives - "An initiative measure embracing more than one subject may not be submitted to the electors or have any effect".  Cal. Const. Art. II, § 8(d).

The Nevada Constitution has similar single subject restriction with respect to legislation - " Each law enacted by the Legislature shall embrace but one subject, and matter, properly connected therewith, which subject shall be briefly expressed in the title . . . ".  Nev. Const. Art. 4, § 17.  The single-subject restriction applicable to initiatives is statutory - ""[e]ach petition for initiative or
referendum must . . . [e]mbrace but one subject and matters necessarily connected therewith and pertaining thereto".  NRS 295.009)(1).  

The difficulty with these single-subject cases is identifying whether a statute or proposal involves just one subject.  Last week, the Nevada Supreme Court considered whether an initiative proposing (1) nonpartisan open primaries, and (2) general election ranked-choice voting involved one or two subjects.  Helton v. Nev. Voters First PAC, 138 Nev. Adv. Op. 45 (2022).   The Court concluded even though the initiative proposes two changes, the single-subject requirement was not violated because those changes are functionally related and germane to each other and the subject of the framework of how specified officeholders are presented to voters and elected.