There are numerous reasons why some actors have to be replaced.
Some stars step in to play the same character after scheduling conflicts arise and the original actor has to leave. Sometimes the celebrity doesn’t agree with the script and leaves of their own accord. Other times some set drama results in an actor being fired, and new character is introduced.
We’ve compiled 29 instances of actors stepping in for each other for various TV and film projects. See how many you knew.
Eric Forman's older sister Laurie was played by Lisa Robin Kelly for most of her time on 'That '70s Show,' but she was replaced with Christina Moore on season six.
Kelly was introduced as Laurie during season one of 'That '70s Show,' but abruptly left the show during season three and was written out by having Laurie go off to beauty school. Kelly briefly returned on season five but was replaced by Moore for a couple episodes of season six.
In a 2012 interview, Kelly told ABC News that she left because of alcohol abuse brought on by the loss of a child.
'I had lost a baby,' she said. 'As a result of that I lost it. I lost everything and I was abusing alcohol. With 'That '70s Show,' I was guilty of a drinking problem. And I ran.'
'Riverdale's' Reggie Mantle was played by Ross Butler on season one and Charles Melton on season two.
Butler had to leave his role on The CW show due to scheduling conflicts with '13 Reasons Why.'
Melton told INSIDER that he didn't focus on Butler's portrayal of the character on the first season because he was told not to.
'I went in during the audition process, it was like the second audition, and I had a session with Roberto,' Melton said. 'I watched the show to kind of get a feel of it, and Roberto (Aguirre-Sacasa) was like, 'Don't watch anything. Don't watch what Ross (Butler) did. What you're doing is completely different.' He was steering me to not throw myself off by trying to emulate somebody else.'
Foy has played Queen Elizabeth for the first two seasons of the Netflix drama, but because the third and fourth seasons are set to portray the middle-aged Queen, a casting change was needed.
James Kent on 'True Blood' was played by Luke Grimes on season six and Nathan Parsons on season seven.
When Grimes suddenly left the show, HBO issued a statement saying it was due to 'the creative direction of the character.' BuzzFeed later reported that he left because he was unwilling to play a gay character, and the writers weren't willing to change the character's romantic future with Lafayette. Grimes' publicist told BuzzFeed it was scheduling.
'Once Upon a Time' aged up Henry Mills by 10 years for season seven, so Andrew J. West stepped in for Jared S. Gilmore.
Helene Beesly first made an appearance on season two's second episode, 'Sexual Harassment,' played by Shannon Cochran. Linda Purl took over as Helene on season six with the 'Niagara' episodes.
Rebecca 'Becky' Conner-Healy, Roseanne's oldest daughter on 'Roseanne,' went through some changes as the actress changed back-and-forth a few times.
Lecy Goranson was cast as the original Becky and played her through season five, but she quit the show to attend Vassar College and Sarah Chalke came in to replace her. The show was expected to end with its eighth season, so Goranson returned with Chalke and her alternating the character as a running gag.
Chalke then continued as the character during the show's ninth and final season. With 'Roseanne' returning to TV for a revival, Goranson is set to reprise her character and Chalke will return in a different role.
'Doctor Who' is on its 13th incarnation of its titular character. Jodie Whittaker was announced as the first female doctor in 2017 and replaces Peter Capaldi.
Peter Capaldi portrayed the Time Lord for three seasons. The Doctor's ability to regenerate his body allows the character to easily be portrayed by numerous actors over time.
Trudy Monk, Adrian's beloved wife on 'Monk,' was played by Stellina Rusich through the first two seasons but was cast as Melora Hardin from season three on.
Rusich played Trudy in a lot of short flashbacks. When they decided to recast for a more significant role, the producers looked for an actress who looked similar to Rusich. After narrowing the search down to five actresses, they chose Hardin.
'(She) just knocked us out. She had an angelic quality without being too syrupy or heavy-handed,' director Randy Zisk said in 'The Official Episode Guide.' 'It's a softness that we like, because Trudy would definitely have that quality.'
On 'Game of Thrones,' Gregor Clegane, otherwise known as The Mountain, has been played by three different actors during the show's seven seasons.
Fans first met The Mountain when he was played by Conan Stevens on season one. He was recast for season two and Ian Whyte took over. Whyte has played a few other characters on the HBO show, including some White Walkers and the giant Wun Wun. Strongman Hafþór Júlíus Björnsson took over once more in season three and has stayed in the role since.
Also on 'Game of Thrones,' sellsword and Daenerys Targaryen's lover Daario Naharis was played by Ed Skrein on season three and replaced by Michiel Huisman for seasons four through six.
When Daenerys first met Daario, Skrein portrayed the sellsword. But the actor chose to step away from the series to pursue a film career. He was cast in 'The Transporter: Refueled.' Huisman then stepped in.
Janet Hubert-Whitten played the first Vivian Banks on 'The Fresh Prince of Bel-Air' but was replaced by Daphne Maxwell Reid after season three.
Hubert's exit from the show was controversial, and was due in part to a feud with executives and Will Smith. In 2011, she told TMZ she would never do a reunion with the cast because 'I will never do anything with an arsehole like Will Smith.' Star Alfonso Ribiero shared a cast reunion photo again in 2017 and Hubert went on another tirade against the cast.
'I have no interest in seeing any of these people on that kind of level,' she wrote on her Facebook page.
Nick Jonas guest starred as Ryan Vogelson on 'Last Man Standing' during season one, but his character was recast on season two with Jordan Masterson taking over.
Erinn Hayes played Donna Gable on 'Kevin Can Wait,' but her character was killed off after season one and Leah Remini became the new female lead.
Fans weren't pleased with how her death played out, and star Kevin James' reasoning for why she was killed has also been poorly received. Remini didn't take over the character role, but she did replace Hayes as a regular on the CBS sitcom.
'Hannibal' recast Mason Verger between seasons two and three with Joe Anderson replacing Michael Pitt.
Katie Holmes played Rachel Dawes, Batman's friend and love interest in 'Batman Begins,' but didn't return for the sequel and was replaced by Maggie Gyllenhaal in 'The Dark Knight.'
Holmes declined to return for the sequel in order to pursue other projects, but she told MTV that she didn't regret her decision.
'I had a great experience working with Chris Nolan (and) I'm sure it's going to be a great movie, (but) I chose to do this movie ('Mad Money'), and I'm really proud of it,' she said,
Jake T. Austin played Jesus Adams Foster on 'The Fosters,' but Noah Centineo replaced him on season three.
Rachelle Lefevre played Victoria in the first two 'Twilight' films, but was replaced by Bryce Dallas Howard in the third.
Lefevre said she was 'stunned' by the news that she was to be recast in the 'Twilight' movies in a statement to Access Hollywood.
'I was fully committed to the 'Twilight' saga, and to the portrayal of Victoria. I turned down several other film opportunities and, in accordance with my contractual rights, accepted only roles that would involve very short shooting schedules,' she said. 'I was happy with my contract with Summit and was fully prepared to continue to honour it. Summit chose simply to recast the part.'
The studio responded and said it was due to her withholding her scheduling conflicts from them.
The character Capheus 'Van Damme' Onyango on Netlfix's 'Sense8' was recast between seasons one and two.
Aml Ameen played the sensate on the show's first season, but it was announced that he was being recast for the show's Christmas special and subsequent second season. Deadline reported at the time of his departure that 'creative differences' led to the switch. Toby Onwumere was cast within a week due to Ameen's abrupt departure.
Rachel Weisz played Evie in 'The Mummy' and 'The Mummy Returns,' but was replaced by Maria Bello in 'The Mummy: Tomb of the Dragon Emperor.'
Terrence Howard played Iron Man's friend James 'Rhodey' Rhodes in the first 'Iron Man' movie, but didn't return for the sequel and was replaced by Don Cheadle.
During an interview on 'Watch What Happens Live,' Howard revealed that the money offer he had originally received for the movie deals weren't up to par when he went to resign for the second one -- and blamed star Robert Downey Jr. for the difference.
'It turns out that the person I helped become Iron Man...when it was time to re-up for the second one, (he) took the money that was supposed to go to me and pushed me out,' he said. 'We did a three-picture deal, so that means that you did the deal ahead of time. It was going to be a certain amount for the first one, a certain amount for the second one, a certain amount for the third. They came to me with the second and said, 'Look, we will pay you one-eighth of what we contractually had for you, because we think the second one will be successful with or without you.' And I called my friend -- that I helped get the first job -- and he didn't call me back for three months.'
Cheadle has played Rhodey/War Machine in all subsequent films.
Eric Bana was Bruce Banner in 2003's 'Hulk,' but was replaced by Edward Norton in the 2008 reboot 'The Incredible Hulk.' Mark Ruffalo has played the green superhero since 'The Avengers.'
Marvel reacquired rights to the character after Bana's turn in 2003. Instead of a sequel, the Hulk was rebooted with Norton. Marvel decided to recast the Hulk once more and Ruffalo stepped in. He's played the hero since. In a 2014 interview with NPR, Norton said he was glad he wasn't involved with the superhero anymore.
'My feeling was that I experimented and experienced what I wanted to. I really, really enjoyed it,' he said. 'And yet, I looked at the balance of time in life that one spends not only making those sorts of films but then especially putting them out, and the obligations that rightly come with that…I think you can sort of do anything once, but if you do it too many times, it can become a suit that's hard to take off, in other people's eyes.'
Mae Whitman is known for playing Ann on 'Arrested Development, but Alessandra Torresani played the character for her first appearance on season one.
According to Flavorwire, series creator Mitch Hurwitz thought about having a different actress play Ann in each episode to show how 'unmemorable' she was, but they ended up just having the two actresses.
Richard Harris played Albus Dumbledore for the first two 'Harry Potter' films before Michael Gambon took over.
Harris died after the second movie had been filmed. He was 72.
Kaitlin Cooper on 'The O.C.' was first played by a young Shailene Woodley before being replaced by Willa Holland.
Kaitlin was shipped off to boarding school during season one and Holland began playing the character when she returned for the third season.
After eight seasons, Charlie Sheen's character was killed off of 'Two and a Half Men' and Ashton Kutcher stepped in for the show's final season.
Shannen Doherty left 'Beverly Hills, 90210' after four seasons and was replaced by Tiffani Thiessen.
Doherty was fired from the show and was known to not get along with the cast and crew. According to Entertainment Weekly, Doherty cut her hair halfway through filming an episode without informing anyone, and that was the last straw.
Shannen Doherty also starred on 'Charmed,' but the actress left after three seasons and Rose McGowan joined the cast for five seasons.
Doherty's character was killed off after it was decided that she would be leaving the show early. According to ABC News, Spelling TV made a statement urging Doherty to pursue other projects.
'We have had a long and prosperous relationship with Shannen and we didn't want to hold her back from what she wanted to do,' the statement read.
In an interview following her departure Doherty said, 'There was too much drama on the set and not enough passion for the work. I'm 30 years old and I don't have time for drama in my life anymore.'
McGowan joined the cast as the long-lost younger sister.
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