The character has been described as popular among teenagers and young adults, not only for his skill at basketball but for his romantic aspirations. Specifically regarding the character's impact on female viewers, Entertainment Weekly stated, "Look into those soulful blue eyes and it's clear why One Tree Hill, in which Murray plays [the brooding basketball star], became a sleeper hit during its first season on The WB."

Chad Michael Murray was the first person to be cast for One Tree Hill. The producers were originally unsure as to who Murray would play. Series creator Mark Schwahn wanted him to play the character of Nathan Scott since Murray had played a bad guy several times before, and he felt it was only natural to give him this role. Murray, however, wanted to portray Lucas due to a connection he felt with the character. He felt that he could inhabit the character as the two share several similarities. Murray's mother left him when he was young, and Lucas was abandoned by his father. Murray's passion for the role led the producers to cast him as Lucas. Murray had turned down the lead role of Ryan Atwood in The O.C. to accept the role as Lucas Scott.

Schwahn said that in designing the show, he created Lucas as "this underdog kid from the wrong side of the tracks" who crosses over to the pretty and popular; he wanted to show what the life of such a person would be like in a basketball atmosphere.

For Murray, in addition to their shared abandonment issues, Lucas's love for literature also appealed to him. Murray had become a fan of the genre during high school, and felt it changed his way of seeing things; it made him rethink his own actions. Lucas has been described as "caught between being charming and a nerd, a hermit and confident". Murray said of the character, "He's very introverted." He described Lucas as an observer, someone who likes to watch people and try and figure out who they really are, as opposed to who they think they are, another aspect similar to Murray's own personality.

Murray never played much basketball before the show, and was more into football while in high school. Because of this, a basketball coach was hired for Murray in order to improve his basketball skills. To go along with the character's personality a "sedate" wardrobe was designed. Schwahn said of Lucas's wardrobe, "...He was a Levi's guy. He was, you know, he wore a lot of, like, plain T-shirts and things because we just wanted him to represent the everyman." Despite having the character start out this way, the series eventually let his wardrobe evolve. Starting from the fourth season on, he was given some "wilder stuff". Schwahn clarified, "You know, he can [now] rock something from Sean John, which normally would have been Nathan's department." He said the style of the characters really does evolve on the show, especially with the four-year timeline jump. "Diesel is so wonderful on [Murray]. Diesel jeans. It’s an Italian company. A lot of times, Italian designers cut much more slimly...for a really lean physique," stated One Tree Hill’s costume designer, Carol Cutshall. "Also, this year, they’ve had nice long sleeves and nice long shirts and really slim clothing and that looks best on [Murray]. He doesn’t need to be swallowed up. He’s got his own style as a person. It’s not just up to me. I try to bring in what I think is going to fit him best." With the timeline jump, Lucas’s main brands become Diesel, Guess menswear, and Juicy Couture for men.

Regarding the character's romantic life, Schwahn designed a love triangle between Lucas and the two girls, Peyton Sawyer and Brooke Davis, which created an intense fanbase rivalry. While describing Lucas and Peyton as soulmates and a "meant to be" pairing, he described Brooke and Lucas as "also genuine" and as having a great dynamic. He acknowledged the fanbases as large and "very passionate" about their pairings. "There is a huge fanbase dedicated to Brooke and Lucas, and sometimes [those people] feel a bit betrayed, just as the fanbase dedicated to Peyton and Lucas felt betrayed [in Season 2, and parts of Season 3]," said Schwahn. "That tells me that we've done things correctly — that's the strength of a love triangle."

Lucas Scott is the son of Dan Scott and Karen Roe, and the nephew of Keith Scott; he has a younger half brother, Nathan Scott, on his father's side and a younger half-sister, Lily Roe Scott, on his mother's side (she is also his cousin through Keith). He was raised by his mother after his father abandoned them to marry Deb Lee, Nathan’s mother. His uncle Keith, who always had feelings for Karen, took over the father figure role. Lucas grew up in Tree Hill, a small North Carolina town along with his best friend and later sister-in-law, Haley James Scott. He shares romantic bonds with Peyton Sawyer and Brooke Davis, is interested in basketball and literature, and suffers from the genetic heart disease hypertrophic cardiomyopathy.

At the beginning of the first season, 16-year-old Lucas Scott is recruited by coach Whitey Durham to play for the Ravens basketball team after most of the players are suspended for drunk-driving. He soon has troubles with his half-brother Nathan, who is also the Ravens captain, because Nathan wants to remain the star of the team and feels threatened by Lucas's arrival. Encouraged by Dan, who also wants Lucas off the team, Nathan and his teammates make life difficult for Lucas, on one occasion kidnapping him and throwing him into a ditch. Nevertheless, Lucas is determined to stay on the team (although he removes the name "Scott" from his jersey). He is attracted to and shares a deep emotional connection with Peyton (Nathan's girlfriend). Disgusted by Nathan's behavior towards his brother, she eventually breaks up with him. Nathan retaliates by pursuing Lucas's best friend Haley, who agrees to tutor Nathan in return for him leaving Lucas alone. Lucas and Peyton fall in love, but Peyton is initially scared of a romance with Lucas (not wanting to be "serious" with him). Lucas starts seeing Peyton's best friend, Brooke, at the same moment Peyton realizes she has made a mistake in turning Lucas away. He soon cheats on Brooke with Peyton, though sex is never involved in the betrayal. On the night that Lucas and Peyton are about to tell Brooke about their affair, Lucas and Keith are involved in a car accident, and, for the first time in the series, Dan calls Lucas his son so that Lucas can get immediate treatment. Lucas wakes up from a short coma and wants to be with Peyton, but Peyton ends their affair for Brooke's sake after Brooke finds out about their tryst. Lucas's feelings towards Dan are challenged when he learns that Dan wanted joint custody of Lucas, but Karen refused. He also finds himself in Dan's position when Brooke claims to be pregnant, although this turns out to be false as Brooke was lying to seek her revenge on Lucas for breaking her heart, and his friendship with Peyton broken once she learns he had a one-night stand with new resident Nicki not long after she ended their affair. However, his relationship with Nathan improves as Lucas realizes that he got a better deal than Nathan, who is damaged as a result of being raised by Dan. Wanting a fresh start, Lucas decides to leave town with Keith. Lucas and Nathan have a final conversation where Nathan calls Lucas his brother and Lucas says, "I'll miss you, little brother." Before leaving with Keith, he goes to say goodbye to Haley and discovers that she and Nathan have married.

In Season 2, Lucas and Keith return to Tree Hill after Dan has a heart attack. Lucas tries to make up for his behavior with Peyton and Brooke and becomes friends with both of them. He also starts seeing a new girl named Anna Taggaro, but they break up amicably when Anna is confused about her sexuality. Lucas realizes that he has romantic feelings for Brooke and begins to focus on building on a relationship with her, even though she is seeing Anna's brother Felix. Lucas discovers that he has inherited Dan's heart condition, but does not tell anyone except Dan. After discovering that Keith's new girlfriend Jules was actually hired by Dan to break Keith's heart, Lucas agrees to move in with Dan if he leaves Keith alone and pays for Lucas's heart medication. This sets Lucas at odds with his mother, as she cannot believe that Lucas would want to live with Dan rather than her. It also causes a new rift between Lucas and Nathan, as Nathan feels that Lucas is replacing him and is bitter about Haley's departure to go on tour singing. Lucas and Karen are reconciled when she learns half of the reason he is staying with Dan, which is to protect Keith. This plan to protect his uncle fails when Jules leaves Keith at the altar and Keith leaves town after discovering that Lucas and Karen knew that she was hired by Dan. Lucas discovers Deb's painkiller addiction and decides to avenge all of Dan's victims. He finds a stash of cash and an incriminating ledger in the attic at Dan's dealership and plans to expose Dan's illegal dealings, but ultimately fails as Dan has also incriminated Deb. Dan then reveals that the whole thing was a set-up to test Lucas's loyalty, which Lucas failed. As a result, he loses Dan's college fund for him (which Dan had been saving since Lucas was a baby) and even his heart medication. Nathan also ends his friendship with Lucas after discovering that Lucas had planned to bring Dan down and visited Haley behind his back in an attempt to patch up her and Nathan's marriage. Lucas does, however, kiss Brooke in the season finale and confesses that he wants to be with her, but she still leaves for California to spend the summer with her parents. Ultimately, it is just Lucas and a broken-hearted Peyton (after boyfriend Jake left her) for the summer and the last shot is of the two of them sharing a meaningful hug on the beach.

In Season 3, after the summer, Lucas remains at odds with Dan, who accuses Lucas of starting the fire at the dealership that nearly killed him. Dan tries to strangle Lucas on the basketball court, but Peyton, having learned the truth from Lucas, tells Dan that Lucas actually saved him from the fire. Lucas also protects the true arsonist: Deb. Lucas and Nathan continue to argue over Nathan's treatment of the returned Haley and have a public fight after Lucas accuses Nathan of being just like Dan. Lucas struggles to pay for his heart medication and steals money from his mother, which Haley sees, forcing Lucas to tell her about his condition. He begins a non-exclusive relationship with Brooke and uses Rachel Gatina to make her jealous, but a series of events leads Brooke to sleep with Chris Keller, tearing them apart. Later, he forgives her after she gives him the 82 letters she wrote to him during her vacation but did not send. He and Nathan gradually become friends again. Keith returns, and he and Karen finally get together and become engaged. Keith also plans to adopt Lucas. Tragedy strikes when Lucas's former friend Jimmy Edwards brings a gun to school and fires it, accidentally hitting Peyton and causing a lockdown ("With Tired Eyes, Tired Minds, Tired Souls, We Slept"). Lucas saves Peyton and is devastated by Jimmy and Keith's eventual deaths. After seeing the effect of Keith's death on his mother, Lucas decides to finally tell Whitey, Nathan, and Karen about his heart condition and quits basketball. He goes on a university tour with his mother and realizes that he wants to become a writer. He is also Nathan's best man for his second wedding to Haley. He and Brooke break up for good during the wedding when Brooke learns that Lucas kissed Peyton back during the school shooting.