Supreme Court (SCOTUS)
The US is 9 seats. It is US-only. Holding a justice seat does not occupy your current office: you can sit on the Court and still be a Senator, governor, or private citizen.
Seats
Each seat has a current occupant (a player, an , or a scripted historical justice) or is vacant.
Until a seat's first live confirmation, it replays an Original Roster: historical occupants succeed each other on authored years with no vacancy gap. The first presidential nomination that confirms a new justice is the divergence point for that seat. After that, succession is in-game.
Nomination and confirmation
The President nominates. The Senate confirms by simple majority, using the same seat-weighted Senate vote machinery as cabinet confirmation. See Confirmation Process.
A justice seat is not a cabinet office and is not gated by year the way HUD or Homeland Security are.
Docket
Curated historical cases resolve against the sitting Court on the calendar year the world actually shows, not the raw turn counter. A majority on the case's tagged axis can diverge from the historical outcome; a divergence can enact policy through the same bill-enactment pipeline as legislation. An evenly split bench (4-4, or no seated majority at all) reaches no decision: the case affirms the existing outcome and history is unchanged.
Surprise cases can also fire: non-historical docket items that resolve the same turn they spawn. They still produce a ruling from the sitting majority.
Tenure
Scripted historical occupants leave when their authored departure is reached. After divergence, a sitting justice (player or NPP) can leave mid-term; the President and occupant are notified when a seat opens. The Court does not keep a confirmed player forever.
See also: Bills & Legislation, Cabinet, Impeachment.