This article/section contains information officially created to be part of the Lost mythos
but ultimately rejected. It may be endorsed by ABC, or feature cast members.
Throughout Lost's six year run, the writers considered several storylines that eventually didn't make it on the show for various reasons. These abandoned storylines are listed here.
Jack's death and Kate's role
In the show's original draft, the character of Jack was intended to be played by Michael Keaton, and he was supposed to be killed by the Monster in the Pilot. The role of the survivors' leader would then be taken over by Kate, who was conceived as a woman in her late twenties/early thirties whose husband was in the tail section. However, the studio executives expressed disinterest in this, guessing that the audience would feel betrayed by investing in a main character, only for him to be killed.
However, once these changes were incorporated into the script, Michael Keaton backed away from the offer, not wishing to take on a full-time television role. Subsequently, Matthew Fox auditioned for Sawyer, but the producers instead casted him for the role of Jack, with the pilot dying in the first episode and some of the ideas originally intended for Kate's character moved to a new character, Rose, whose husband Bernard was in the tail section. (Before They Were Lost)
Cindy was supposed to be the crew member whose body Shannon cried over in "Pilot, Part 1". However, this was ultimately scrapped. This later worked to the advantage of the writers, who needed a crew member to tell the tailies they were flying off course before the crash in Season 2. They chose Cindy as that crew member.. [source needed]
Sawyer and Charlie
Originally conceived as a suit-wearing con-man and an older "has-been" rock star, the characters of Sawyer and Charlie were changed to better fit the actors cast in their roles. Sawyer was made more feral based on Josh Holloway's appearance, and Charlie was made a younger "one hit" rock star, based on Dominic Monaghan's age. (Before They Were Lost)
Richard and Marybeth
According to the original script, a couple named Richard and Marybeth would be introduced as two survivors in "Confidence Man". Richard was 50s, and Marybeth was 40s. Marybeth was to have an asthma attack, and her husband Richard would then pillage Sawyer’s stash to find her asthma inhaler. But this storyline was changed, giving Shannon an asthma attack, with her brother Boone attempting to pillage Sawyer's stash. 
Claire's surrogate pregnancy
Claire was originally intended to be a surrogate mother for her friends Ruth and Stewart, though at some point between the casting of Emilie de Ravin and the start of production, this was changed to her being pregnant with her own baby. (Before They Were Lost)
Ben's and Desmond's limited roles
At the start of season 2, both Ben and Desmond were characters that were supposed to appear for only three episodes each. Following the extremely positive response to Michael Emerson's and Henry Ian Cusick's  performances and characters, both were expanded. Ben appeared in five more episodes that season,  and was promoted to a season regular the following year.  The writers decided to bring Desmond back for the finale of season 2 (Official Lost Podcast/February 20, 2007), in which he was also granted centricity and flashbacks detailing his arrival on the Island. For this, his backstory with Penny and Charles Widmore, two characters whose importance to the show grew in the following seasons, was created.
"Tampa job" flashbacks
Before being changed to a Michael-centric episode, "Adrift" was written as a Sawyer-centric episode, with a flashback focusing on the "Tampa job," featuring a second appearance by Hibbs and a character played by Jolene Blalock, with whom Sawyer falls in love after meeting her in Florida. These flashbacks were shot, though removed due to the producers' extreme dislike of them. 
Beatrice Klugh was originally intended to be the one Sun shot in "The Glass Ballerina", but for some reason, likely due to actress April Grace's unavailability, Colleen was created and killed in her place. 
Nikki and Paulo's role
Nikki and Paulo were originally supposed to be part of a longer story arc, with one episode having its flashbacks devoted to Nikki's fictional television show, Exposé, to end with a surprise twist (presumably revealing that those "flashbacks" were merely part of a television show Nikki was acting in). Faced with the negative fan backlash to the two characters' abrupt introduction, however, the producers, already facing declining ratings for the show, decided back in December 2006 to trim down the storyarc and kill off the two characters in a single episode. 
The science team's individual flashbacks
Prior to its shortening due to the writer's strike, Season 4 was supposed to feature three more episodes, focusing on the science team's members Daniel Faraday, Miles Straume, and Charlotte Lewis.  After having their individual centric episodes cut, the trio shared a centric episode with non-main characters Naomi Dorrit and Frank Lapidus. ("Confirmed Dead") Later, Miles' and Daniel's full flashback episodes were moved to Season 5, while Charlotte's past was explored through dialogue and time travel.
Originally, it was reported that Danielle Rousseau, a recurring character in the first four seasons, would have a flashback in the fourth season. However, after she was killed, Rousseau's backstory was instead explored with time travel in the show's fifth season. (Official Lost Podcast/August 2, 2007)
After being promoted to a main character, Ilana was supposed to be revealed as Jacob's daughter, a plot line eventually dropped by the producers due to lack of time. Instead, she was made a person to whom Jacob acted as a father figure, explaining her emotional reaction to his death. She was killed-off mid-season after recruiting some of the candidates and explaining Jacob's and MiB's plans for them, "once the island was done with her".
Caesar was originally intended to become a regular in the fifth season, along with Ilana. However, Saïd Taghmaoui could not commit to an entire season, and thus his character was abruptly killed in his fourth appearance. Afterwards, he was offered a star billing in the sixth season, with his character having a big role in the flash-sideways and the series finale, though Taghmaoui once again refused and his character never reappeared after his death in "Dead Is Dead". 
The producers intended to have Mr. Eko on the show for at least four seasons, in which he would have discovered his spirituality and represented another spiritual force on the Island, playing a major part in the show's overall story and mythos. They had to write out the character after Adewale Akinnuoye-Agbaje decided to move out of Hawaii following the death of his parents and dislike of living in the area. After his departure from the show, some of the elements from his arc were moved to Locke's, though it has never been stated which ones exactly. Akinnuoye-Agbaje was also in talks to return in Season 6, but the producers could not meet his salary demands.
- ↑ The original script of Confidence Man
- ↑ Parade: A Lost Cause?
- ↑ LA Times: Michael Emerson's 'Lost' world Denise Martin, September 09, 1998
- ↑ Boston Globe: Back to the land of the 'Lost'
- ↑ DarkUFO: Damon Lindelof and Carlton Cuse speak at Screenwriting Expo
- ↑ Kristin Dos Santos: The Death that wasn't meant to be
- ↑ Entertainment Weekly: 'Lost' in Transition
- ↑ Entertainment Weekly: 'Lost': Secrets from the Set!
- ↑ Washington Post: 'Lost' revelation: Was Ilana Jacob's daughter? Jen Chaney, 05/21/2010
- ↑ Télécâble Sat Hebdot: Saïd Taghmaoui ne reviendra pas dans LOST Cédric Melon; 12/03/2009
- ↑ DarkUFO: Damon Lindelof on Libby, The Numbers, Mr Eko and more
- ↑ http://spoilerslost.blogspot.com/2009/09/some-season-6-snippets.html
- ↑ E! Online: "Lost's Mr. Eko Turned Down Finale Guest Spot!" Kirsten Dos Santos, May 24th 2010