Big Brother 20


 * Similar to Big Brother 19, four (technically five) returning housemates re-entered the house on launch night: Erica from Big Brother 12 and Big Brother 15, Natalie and Summer from Big Brother 18 competing as one housemate, Allen from Big Brother 14, and Ty from Big Brother 11.
 * After all of the housemates entered the house, Big Brother informed them of a timebomb task, where one housemate would receive a free pass to the final, one would be nominated in every eviction, and one would be evicted immediately. Callum was granted a free pass to the final, Brian was nominated forever, and Arianna was automatically evicted.
 * Callum was punished in Week 5 by competing against other housemates for his final pass. Troy won the pass at the end of the week.
 * In Week 6, Amy from Big Brother 4 and Craig from Big Brother 17 entered the house along with Arianna and new housemate Charley.
 * In Week 8, Joe from Teen Big Brother 7 entered the house by winning a special fan poll.
 * In Week 10, Pauline from Big Brother 12, Michelle from Big Brother 17, and evictee Natalie & Summer entered the house alongisde new housemate Felicia by winning a special fan poll.