Fox is making a major change to the format of its ambitious reality experiment Utopia. EW has learned exclusively that soon the show’s castmates will start voting each other out—and pick new members to join their fledgling society.

The decision represents a twist in the series, which launched as a rather unique format for a broadcast network reality show in that there was no competition element, elimination ceremony, or grand prize (all ways that producers traditionally boost the stakes of a reality show). But Utopia has struggled in the ratings during its first four weeks on the air. Though producers have previously maintained that cast changes would likely happen along the way, only within the last week has the new format been decided. Fox hopes the changes will heighten the show’s on-camera action without disrupting Utopia’s central premise of showcasing a diverse group trying to build a perfect society in a remote location.

Here is specifically how the format change will work: Next week, the current cast of 15 pioneers will select two candidates for exile, plus Utopiatv.com passport members can choose a third. The Utopians will then decide which of the three candidates will be asked to pack their crate and leave. Two new potential Utopians will arrive at the camp and spend several days vying for the open spot. Then the established cast will decide which new candidate will become a full-fledged member of their society.

How often the cast will vote a cast member out has yet to be determined. Unlike CBS’ Big Brother or Survivor, the vote-out is not expected to be weekly event. The producers currently believe the cast shake-up will be held monthly, though that could change depending how viewers respond.