Big Brother 4 is the fourth season of the reality television series Big Brother. The format of the program remained largely unchanged from previous seasons: a group of contestants, referred to as HouseGuests, are enclosed in the Big Brother House under the surveillance of cameras and microphones. Each week, the HouseGuests vote to evict one of their own until two HouseGuests remain on finale night. The winner will be decided by the last seven evicted HouseGuests, collectively known as the Big Brother Jury. Julie Chen returned to host this season. The winner of the series won a $500,000 grand prize, while the runner-up won $50,000. This season was also broadcast on E4 in the United Kingdom, beginning near the end of that country's fourth series.
Format
HouseGuests are sequestered in the Big Brother House with no contact to or from the outside world. Each week, the HouseGuests take part in several compulsory challenges that determine who will win food, luxuries, and power in the House. The winner of the weekly Head of Household competition is immune from nominations and must nominate two fellow HouseGuests for eviction. After a HouseGuest becomes Head of Household, he or she is ineligible to take part in the next Head of Household competition. HouseGuests also take part in food competitions in which they must win in order to eat regular foods. Losers of the competition are put on a peanut butter and jelly diet. The winner of the Power of Veto competition wins the right to save one of the nominated HouseGuests from eviction. If the Veto winner exercises the power, the Head of Household must then nominate another HouseGuest for eviction.
On eviction night, all HouseGuests except for the Head of Household and the two nominees vote to evict one of the two nominees. This compulsory vote is conducted in the privacy of the Diary Room by the host Julie Chen. In the event of a tie, the Head of Household must publicly cast a deciding vote to resolve a tie. Unlike other versions of Big Brother, the HouseGuests may discuss the nomination and eviction process openly and freely. The nominee with the greater number of votes will be evicted from the House on the live Thursday broadcast, exiting to an adjacent studio to be interviewed by Chen. HouseGuests can be removed from Big Brother for any rule violation or exhibiting disruptive behavior such as violence, or may voluntarily leave the house but they are not allowed to return to the game, such as the case of Scott Weintraub during the season.
Some changes from previous seasons were implemented throughout the course of the game. The main twist for the year was The X-Factor. Eight HouseGuests were introduced, only to have five HouseGuests' exes compete against them in the game. Another change in the format, introduced in the last veto contest of Big Brother 3, was the Golden Power of Veto, in that if a nominated person won such a veto, they would be allowed to take themselves off consideration for voting, which was not allowed when the veto was introduced originally the year before, in addition to casting a sole vote for eviction during the Final four. Since its inclusion, the Golden Power of Veto has appeared in subsequent seasons, albeit with only minor changes.
Due to a possibility of a tie and an America's vote is required to resolve a tie, a change was made to the Jury beginning this season whereas the Jury was reduced to the last seven evicted HouseGuests (which would remain until season 14 before expanding to nine members) who formed the jury that determined the eventual outcome. Unlike previous seasons where the evictees were sent back home and could watch the series freely, jurors were placed in a sequestered house, but were not be allowed to watch the show except for competitions and ceremonies that include all of the remaining HouseGuests. They were still have entry to the Diary Room but footages of the interviews, including potential strategy or details regarding nominations, were not shown on air.
HouseGuests
Thirteen HouseGuests were cast for this season of Big Brother. One of the original selections, Brandon Showalter, of Newport Beach, California, was kicked off of the show during the sequester period after it was revealed he had communicated with his girlfriend. As part of this season's twist, five of the original eight HouseGuests were shocked to find that an ex would be playing the game with them as part of the "Ex-Factor" twist. The exes were Jun and Jee, Alison and Justin, Erika and Robert, David and Michelle, and Amanda and Scott.