The borderlands world functions similarly to a hardcore vanilla world, but players may find that it has quirks that make survival a relentless struggle.
On completion of the game itself (I.E., killing the ender dragon successfully), all players still alive will be given the chance to either continue in the hardcore world as a survival player or become a permanent player of the borderlands (receive creative mode, & residential status). This constitutes 1 cycle in the borderlands, and those who become permanent players will remain so indefinitely, unless they die by supernatural cause.
Those are the rules. Good luck!