Big Brother Australia (Season 1)

Big Brother Australia 2017, also known as Big Brother 1, is the first season of the Australian reality television series Big Brother. It began airing on 8 July 2017 on the Seven Network. Sonia Kruger was announced as the host of the show.

This season revolved around 20 strangers living in a house together with no communication with the outside world as they competed for $250,000. They were constantly filmed during their time in the house and were not permitted to communicate with those filming them. When only three housemates remain, the Australian public decided which finalist would win the grand prize. This season was also the first to be completely pre-recorded before airing, except for a live finale.

Format

 * Nominations: At the start of each round, the housemates compete in a "Nomination Challenge". The winner of the competition has the sole power over the nominations. Immediately after the challenge, the winning housemate will be called to the Diary Room by Big Brother to name three nominees, and provide full reasons for their nominations. When there are 10 Housemates remaining, only two Housemates would be nominated, instead of three.
 * Eviction: On eviction night, all housemates must vote to evict one of the nominees, with the exception of the nominating housemate (who will only cast a tie-breaker vote, if required), nor do the nominated housemates vote when there are only two nominees (on account of their votes cancelling the other's out). The eviction vote is by secret ballot, with housemates casting their votes orally in the Diary Room to Big Brother, and must provide a reason for their vote. The nominee with the most votes is evicted from the house.
 * Finale: The final three housemates will face Australia's vote to determine the winner.