Big Brother follows a group of contestants, known as HouseGuests, who live inside a custom-built house outfitted with cameras and microphones recording their every move 24 hours a day. The HouseGuests are sequestered with no contact with the outside world. During their stay, the HouseGuests share their thoughts on their day-to-day lives inside the house in a private room known as the Diary Room. Each week, the HouseGuests compete in competitions in order to win power and safety inside the house. At the start of each week, the HouseGuests compete in a Head of Household (abbreviated as "HOH") competition. The winner of the HoH competition is immune from eviction and selects two HouseGuests to be nominated for eviction. Six HouseGuests are then selected to compete in the Power of Veto (abbreviated as "PoV") competition: the reigning HoH, the nominees, and three other HouseGuests chosen by random draw. The winner of the PoV competition has the right to either revoke the nomination of one of the nominated HouseGuests or leave them as is. If the veto winner uses this power, the HoH must immediately nominate another HouseGuest for eviction. The PoV winner is also immune from being named as the replacement nominee. On eviction night, all HouseGuests vote to evict one of the nominees, though the Head of Household and the nominees are not allowed to vote. This vote is conducted in the privacy of the Diary Room. In the event of a tie, the Head of Household casts the tie-breaking vote. The nominee with the most votes is evicted from the house. The last seven evicted HouseGuests comprise the Jury and are sequestered in a separate location following their eviction and ultimately decide the winner of the season. The Jury is only allowed to see the competitions and ceremonies that include all of the remaining HouseGuests; they are not shown any interviews or other footage that might include strategy or details regarding nominations. The viewing public is able to award an additional prize by choosing "America's Favorite HouseGuest." All evicted HouseGuests are eligible to win this award except for those who either voluntarily leave or are forcibly removed for rule violations.
Format changes and additions BB Break-in and BB Multiverse On July 28, 2023, CBS released a clip featuring former HouseGuests Frankie Grande from season 16, Britney Haynes from seasons 12 and 14, and Danielle Reyes from seasons 3 and all stars, who were seen "breaking into" the
Big Brother House with a "time laser." According to a press release issued in conjunction with the clip, the trio of former contestants, who all lost their respective seasons, broke into the house in an attempt to "go back in time and change the outcome of their season," which backfired, unleashing the first twist of the season, which would be revealed on the premiere episode.
BB Multiverse The BB Break-in revealed that Grande, Haynes, and Reyes had opened up the BB Multiverse, combining four universes: the Comic-verse, the Humili-verse, the Scary-verse, and the Scramble-verse. There are four rooms in the house, each themed to one of the universes. Additionally, these universes are the basis for the competitions and game twists for the season. The notable game twists and events from each universe are as follows.
Comic-verse •
BB Power of Invincibility: Fans had the opportunity to cast their votes for an extraordinary superpower. The top four vote-receiving HouseGuests would compete in a secret competition for the BB Power of Invincibility. This power would grant the winning HouseGuest the ability to nullify one of the next two evictions, in Week 4 or Week 5, including their own. If the power were used on a HouseGuest not evicted in Week 4, that power would remain active the following week. If the power was successfully used on a HouseGuest, the week would reset, and the outgoing Head of Household could compete in the following Head of Household competition. •
Comic Week: Week 11 was announced as Comic Week, which would superpower the Head of Household and the Power of Veto. •
BB Power of Invisibility: This superpower allowed the Head of Household to remain anonymous to the other HouseGuests and operate in secret for the duration of the week. The Head of Household would also be eligible to compete in the following week's HOH competition, where they would normally be ineligible. •
BB Power of Multiplicity: This superpower allowed for two Powers of Veto to be up for grabs. It additionally allowed the number of Veto competitors to be raised from 6 to 8, including all current HouseGuests.
Humili-verse •
Humili-week: Week 6 was deemed "Humili-week." Immediately following the Head of Household competition, the HouseGuests were informed that everyone, except for the HOH, would be a Have-Not this week, taking turns sleeping in the Have-Not room. This week also had various other punishments for the HouseGuests.
Scary-verse •
Nether Region: On premiere night, the loser of the Scary-verse nomination competition would also be dragged into the "Nether Region" for an undetermined amount of time. Upon this person's return, they informed the rest of the HouseGuests about a message from the Scary-verse: while they had returned relatively quickly, the next person may not be so lucky. In Week 2, the Head of Household competition runner-up was sent to the Nether Region. Upon their return, they had to select one HouseGuest to be sent to the Nether Region; however, this HouseGuest would receive immunity for the week. Upon this person's return, they had to select one more HouseGuest to be sent to the Nether Region. This player would be ineligible to play in the Power of Veto competition. •
Scary Week Double Eviction & Resurrection Week: Week 7 was announced as Scary Week, which unknown to the HouseGuests, resulted in a surprise Fake Double Eviction. Following the Double Eviction, both evictees became "BB Zombies" and returned to the house for the following week, where they had the chance to officially return to the game. During "Resurrection Week", no Head of Household or Veto competitions were held. Instead, both "BB Zombies" competed for an advantage that gave them the option to either compete themselves or force the other "Zombie" to compete in the "Re-Entry" Competition at the end of the week. One would remain and have their game "resurrected", while the other would be officially evicted. •
Trick or Treat Luxury Competition: During the
Halloween special episode of Big Brother 25, the Final 5 competed in
Trick or Treat, where they were told to either give candy to other houseguests' buckets ("treats") or take candy away from them ("tricks"). The houseguest with the most pieces of candy at the end of five rounds would be awarded $5,000.
Scramble-verse •
Nomination Competition & Head of Household Save: On premiere night, the HouseGuests entered in groups of four and each had to pick a spot in a different competition with four options. Instead of competing for the power of Head of Household, they were competing to avoid nomination. The losers of each of the four competitions would be nominated for eviction Week 1. The Head of Household in Week 1 had to choose which two of the four nominated HouseGuests to remove from the block. •
17th HouseGuest: On the official CBS social media pages, it was announced a 17th HouseGuest would be entering the
Big Brother House to play. After the Nomination Competition, the HouseGuests were greeted by Cirie Fields, a four-time
Survivor player, as the 17th HouseGuest.
Smaller jury At the beginning of the Day 44 Head of Household competition, Julie announced that, to commemorate the 25th season, the jury would be going "old school", consisting of only seven HouseGuests (as was the case between seasons 4 through 14), instead of the usual nine (as had been the case between seasons 15 through 24 and as it had been the case with season 26). == HouseGuests ==