Series creator William J. Bell created Victor Newman, Jr. in 1995 as part of a social issue storyline. The plot involved Hope Adams' decision to carry Victor's child to term despite the possibility that he could inherit his mother's blindness, which could manifest later in life. Adam was first portrayed in 1995 by infant actors, including twins Celeste and Coryn Williams, followed by Danielle and Sabrina Helper and then Spencer Klass. Hayden Tank played the role from December 1996 to August 1997, and returned for a guest appearance on June 26, 2002. In 2008, it was announced that the character had been rapidly aged to an adult. Chris Engen assumed the role of Adam on February 21, 2008.
In May 2009, it was announced that Engen was leaving the program and that Muhney had immediately been recast in the role. Muhney made his first appearance as Adam on June 25, 2009. In 2011, Muhney signed a contract that would keep him in the role for an unspecified period. In April 2013, Muhney announced that he had signed a new contract that would expire in June 2015. In December, however, Muhney announced that he had been abruptly let go from the soap opera, with his last airdate on January 30, 2014. In August, it was announced that Hartley had been cast as Adam, due to begin taping in September; he first aired on November 5, 2014. Upon the news of his casting, the actor told TV Guide: "I'm so pumped about joining Y&R — I watch it all the time and can't wait to get in there and get my hands dirty!" In 2016, it was announced that Hartley had been cast in a regular role on the NBC drama series This Is Us, which was picked up by the network, placing his future with The Young and the Restless into question. In September 2016, Hartley confirmed his exit from the soap opera on his Facebook page, thanking fans for their support as well as encouraging them to watch him on This Is Us.
Adam's off-screen background was established to reflect that of his father; the character was highly self-motivated, studying at college and beginning a career in finance. In an interview with Soaps In Depth, Engen said, "Luckily, I'm not going to be compared to anyone else ... anything I do and anything I try to project, and [the] kind of ideas that I have to influence the character are okay". The actor stated his intent to portray Adam as a "rich, three-dimensional character with ambitions, flaws, and the positive qualities of his mother Hope".
As the character's storyline progressed, he became "one of the most devious characters on daytime" as part of a Gothic plot in which Adam secretly torments Ashley, Victor's love interest, to get revenge on his father. The story called for Adam to be blind, with uncertainty whether his condition is genuine. Engen told Julie McElwain of Soaps In Depth that he was not sure how to portray the blindness. He said, "I didn't want to nail it on the head completely with the blindness, because I wasn't sure if the blindness was real. Signy [who portrayed Hope] won awards for her portrayal of retinitis pigmentosa, and I thought it would be a dishonor to that if I came too close to the mark." Engen said that he thought that former executive producers, Maria Arena Bell and Paul Rauch, and the writers "know what they're doing, and right now it would seem like Adam is instigating more ... drama." The actor worried whether the character's actions might lead to him becoming "irredeemable", but also said he took it as a challenge to make what Adam does "interesting and human".
Muhney said in an interview that the plot point of seducing Rafe broadened Adam's horizons. He said, "What it did was move a character who represents a person who lives in Genoa City and moved him outside of a box that you can neatly check off. 'He is straight, he is this, or he is that,' and the fact that some lines are blurred makes him more real. When they did that with this character, I loved the opportunity to play into a different realm which is usually not touched upon on television." Muhney described the character as a "puppeteer" with "survival instinct", but also someone with a conscience. In another interview, when asked what he likes about portraying Adam, Muhney stated: "You want to play a catalytic character. You know a troublemaker is good business. You know someone who doesn't swim with the fishes, who swims upstream in the other direction, is someone who is going to cause friction and turbulence in storyline with other characters. I have been told by many of my cast members that the role to play is Adam. They say, "If I were to have a choice, the character I would want to play is your role, Adam."
Adam's first romance was with Heather Stevens (Vail Bloom), which received viewer support. Engen said that he "thanked God" for that aspect of his storyline, that he felt Adam "genuinely loves" Heather and that she had been "the only light in this world of darkness that the character had lived in" since Engen started portraying the character.
Adam has been involved with his brother's ex-wife, Sharon Newman (Sharon Case)—a relationship which SoapNet described as "dark". Adam stole Sharon's newborn baby, Faith, and gave her to Ashley Abbott (Eileen Davidson)—whom he caused to have a miscarriage and a phantom pregnancy. Despite knowing this and seeing Sharon grieve, Adam bonded with her out of guilt; however, they fell in love and married. Muhney told SoapNet that Adam "unequivocally loves her 100%", and said, "You can argue as much logic as you want about what Adam has done and what he is doing." Sharon remained in love with Adam after his kidnapping of Faith was revealed. The soap's other characters, who viewed him as a criminal, were displeased with the romance. Case described Sharon's ability to forgive Adam as a "tough pill to swallow", and also compared it to Nick's love for Phyllis—who had "blown people up and ran people over". Jamey Giddens of Zap2it described Adam and Sharon's relationship as "inappropriate" yet "red-hot". Several of Sharon's friends, including her ex-husband Jack, disowned her because of the relationship. After Sharon's conviction for the murder of Adam's ex-wife Skye, she escaped after being sentenced to life imprisonment. During this storyline, Case still supported the couple—dubbed "Shadam" by viewers—saying that the pairing "took us all by surprise". Case also said, "That is what I was referring to with this storyline because of the pace and the vitality that "Shadam" has." While on the run, Sharon slept with a man named Sam when Adam thought she was dead. Feeling betrayed, Adam tricked her into a jailhouse wedding where he abandoned her, leaving Sharon heartbroken and angry.
Nicholas—Sharon's first husband and Adam's brother, later forced Sharon to get a restraining order against Adam. The night before it became active, she spent the night with Adam, who vowed to fight the order, refusing to give Sharon up. Jae' Jones from Yahoo! said that Sharon's actions "always" lead her back to Adam. Adam was attacked by Patty Williams (Stacy Haiduk), and his impaired vision returned. Sharon looked after Adam and even returned him to his mother's farm in Kansas where they reconnected. Adam proposed to her and they returned to Genoa City. However, Sharon ended their relationship shortly after learning of Adam's role in freeing Patty—who went on to wreak havoc and hurt loved ones—from a psychiatric hospital two years earlier. Although Sharon knew Adam had changed, she refused to bet anything on him.
Despite Adam's marriage to Chelsea Lawson (Melissa Claire Egan), he helped Sharon after she had a mental breakdown and burned down the Newman ranch. Case said that Sharon's relationship with Nick "held more weight", and that Sharon and Adam is "just as deep". Adam had an arsonist set fire to another building to avoid Sharon being implicated for the fire at the ranch. The arsonist burned down a restaurant owned by Chelsea's father. Chelsea became insecure and bitter towards Sharon, and was enraged at Adam for breaking the law to save Sharon. Chelsea warned Sharon to stay away from Adam; Sharon told her that Adam would never love Chelsea the way he loves her. Luke Kerr of Zap2It said that Chelsea was "out of her league" and the storyline was "fun".
Egan said: "I love working with Michael Muhney. I heard about him because my mom had watched Y&R before I joined. So when I told her my character was going to be mixed up with Adam, she went, 'Oh! He is so good, but so bad'". Egan said that her mother "told me he was a great character, but an evil one, so I was really excited. And now knowing Michael, it has been so much fun." She said that "everyone seems to think we have good on-screen chemistry" and that "it's an interesting energy between Chelsea and Adam being the "bad guys" in town." Egan said Adam was Sharon's biggest supporter when Chelsea had Billy's baby and gave him up.
When news broke of Engen's exit from the show, reporters speculated that he had quit because of personal objections over an upcoming same-sex relationship between Adam and Rafe Torres (Yani Gellman). Commentators—including celebrity blogger Perez Hilton who wrote "homophobe" on an image of the actor—criticized Engen.
In an interview with TV Guide Canada, former executive producer and head writer Maria Arena Bell stated that while she would not comment on Engen's decision, she was "saddened that they had to recast because Engen was really gelling in the role", but added that she had "no doubt" that Muhney would make Adam his own.
In another interview, Eileen Davidson, who portrayed Ashley Abbott, said that she "couldn't judge" Engen's decision since it was a "personal one". Davidson said, "Everybody has his or her own demons—and makes their own choices due to their creative process." In other interviews, Eric Braeden, who portrays Adam's father Victor Newman, stated his disappointment with Engen's departure, and told Soap Opera Digest that he unsuccessfully tried to convince the actor to stay with the soap opera. Braeden stated, "He was somewhat disturbed by the fact that he was playing this evil character. I said, 'Listen, I remember Victor feeding rats to people.' I told him to embrace it because he had the most riveting storyline around, period." In another interview with Soaps In Depth, Braeden said that he too was "saddened by the fact that he left", saying it was a "hell of a role". Braeden also said, "Whatever personal reasons he has, you've got to respect that. But he was a very nice guy, very professional. We all liked working with him. We were shocked when he decided to leave, but that's his personal decision." After the controversy surrounding his departure from the show, Engen posted a message on his Myspace page stating he had been unhappy with Adam's storyline long before the homosexual plot twist had emerged.
After the sudden announcement that Muhney had been fired from the role in December 2013, viewers and critics alike expressed their disappointment in the decision. Michael Ausiello of TVLine wrote that the news was the "worst Christmas present ever", as well as Jamey Giddens of Zap2it writing: "Outspoken and insanely-gifted, Michael Muhney has definitely shaken things up in daytime since joining The Young and the Restless. Whether he was demanding changes in the Daytime Emmy nomination process, or getting into fights with his TV pappy on Twitter, one thing was for certain — Muhney always brought it on screen as bad seed Adam Newman. Well, not anymore." Immediately after the news of his firing, Muhney conducted an interview with the Huffington Post and stated: "Part of me feels this is because I've always been outspoken, and sometimes I've been too outspoken. Sometimes I've walked around with a big backpack full of hubris. That is entirely on me. CBS, Sony, and Jill Phelps are not to blame for that." Muhney also said that the writers were planning to "take a break from Adam for 3 to 6 months" and then recast the role.
In January 2014, however, celebrity gossip site TMZ reported that according to multiple sources that the reason Muhney was allegedly let go from the soap was because Muhney had sexually harassed co-star Hunter King (who portrays Summer Newman). The site wrote: "38-year-old Muhney allegedly bullied and harassed 20-year-old Hunter King, who plays Summer on the show. She went to higher-ups and complained recently Muhney had fondled her breasts on 2 occasions — and she said both were unsolicited and unwanted." The rumor generated significant negative publicity for the soap opera; Margaret Eby of the New York Daily News wrote, "The set of "The Young and the Restless" may have turned into a real life soap opera thanks to star Michael Muhney, who was allegedly fired for groping one of his co-workers." Fox News reported that several viewers were upset by Muhney's firing and the sexual harassment allegations, writing: "Many Y&R fans were none too pleased to find out Muhney was leaving, and several blasted the allegations." TMZ later reported that angered viewers had paid US$785 to have an airplane fly over CBS Studios in Los Angeles with a banner to have Muhney rehired, and the plane flew three days later. Muhney made his final appearance on January 30, 2014. In August 2014, Muhney claimed on his Twitter page that the allegations were indeed false and it was only a salacious rumor.
Hope gives birth to Victor Adam Newman, Jr. in 1995, and soon after she and Victor divorce, prompting Hope to move to Kansas with Victor Jr. He was raised believing Cliff Wilson was his father until June 2002, when Victor visited Kansas to see Victor Jr. Six years later in February 2008, Hope tells Victor that she is dying from pancreatic cancer, and tells their son—known as "Vic"—that Victor is his father. A Harvard Business School graduate, Vic is resentful of Victor for abandoning his own child. He later agrees to move to Genoa City with Victor and work at his company, Newman Enterprises, but still refuses to build a relationship with his father. Vic then begins using the name Adam Newman, and is resented by Victor’s other children Victoria and Nicholas Newman (Amelia Heinle and Joshua Morrow) for splitting up their parents during Victor and Hope’s marriage. Victor's girlfriend Sabrina Costelana (Raya Meddine) urges him to mend his relationships with his children. Adam then begins dating Heather Stevens (Vail Bloom), and Victor’s dislike of her causes their romance to become secretive. When Victor is presumed dead while in Mexico searching for the men responsible for Sabrina’s death, Adam takes over at Newman Enterprises, fires his siblings and instates Victor’s nemesis Brad Carlton (Don Diamont). Adam's family are powerless to stop him after they discover Victor left most of his possessions to Adam in his will. Adam plots to frame Jack Abbott (Peter Bergman) for murder, but when Victor appears alive, Jack reverses the plot and Adam is framed for murder, resulting in his imprisonment. Heather begins to notice Adam’s failing eyesight; he may have inherited his mother’s blindness. After Adam is brutally beaten by an inmate, Victor has the charges against his son dropped.
In 2009, Adam becomes friends with Ashley Abbott (Eileen Davidson), who continuously hears a baby crying and finds things supposedly left for her by Sabrina, who is dead. The housekeeper Estella Munoz (Anne Betancourt) is blamed and arrested; however, Adam was secretly gaslighting Ashley. Adam dresses as Sabrina, scares Ashley and she falls down a staircase, causing her to miscarry her child, whose father is Victor. Adam then blackmails her doctor, Charles Taylor, into telling her that her child was still alive. Rafe Torres (Yani Gellman) is appointed to investigate Adam, who seduces him to divert his attention from Adam's criminal activity. Heather discovers Adam's affair with Rafe and ends her relationship with Adam. Ashley is admitted to a psychiatric hospital, where a pregnant Sharon Newman (Sharon Case) is also staying. Sharon goes into labor and Adam steals her daughter, Faith, and passes her off as Ashley’s child. Sharon believes her child had died, and guilt-ridden, Adam pursues a relationship with Sharon and they elope, but she leaves him when she remembers elements that contradict her losing her child. A note from a dying Charles Taylor saying that Ashley had miscarried and Faith is really Sharon and Nicholas’ daughter is found. Adam is jailed again, but gets the insane Patty Williams (Stacy Haiduk) to help him escape to attend a masquerade ball, where he unsuccessfully begs Sharon for forgiveness. An explosion at the ball occurs and a burned corpse is positively identified as Adam. Nicholas is arrested for Adam's murder. The corpse is actually that of Richard Hightower, to whom Adam had donated bone marrow and carries Adam's DNA. Adam meets up with Skye Lockhart (Laura Stone) and they plot a confidence trick together, but Adam still dreams of Sharon.
Adam and Skye, now married, return to Genoa City to testify on Nicholas’ behalf, but Adam fakes a mental breakdown and is sent to the psychiatric hospital where Patty is being treated. She recollects the night of Hightower’s death to the district attorney, but Adam confuses her, leads her out of the hospital, gives her a new identity and tells her never to return. Adam and Sharon reunite in New Orleans, just before he faces charges for murdering Skye. Sharon travels to Hawaii to prove Skye is alive, but she falls to her death in a volcano and Sharon is arrested for her murder. Adam helps Sharon to escape from prison and flee the state, and she is presumed dead when her burned-out car is found. Sharon is actually carjacked and the carjacker died in the fire. Adam is devastated and still looks for proof that Sharon did not kill Skye. He eventually finds proof but when he discovers that Sharon had been living with a veterinarian in New Mexico, he disposes of the evidence in a river in July 2011. Adam then plots with Diane Jenkins (Maura West) to make Victor suffer, almost framing him for Diane’s murder. However, when Diane's murdered body is found, a six-month investigation ensues with Adam as an initial suspect. Adam again takes over at Newman Enterprises when Victor falsely confesses to the murder, and later reunites with Sharon, but she leaves him again when his scheme against Patty is revealed. Adam later befriends Chelsea Lawson (Melissa Claire Egan) and they begin dating in April 2012, later eloping to Kansas where Sharon tries to stop the wedding. Chelsea becomes pregnant but miscarries in a car accident with Summer Newman (Hunter King). Adam takes in Sharon, who is mentally unstable, and gets her the help she needs; Chelsea disapproves. After he is reinstated as chief executive officer at Newman Enterprises and shares a kiss with Sharon, Adam promises Chelsea they can move to Paris, but when he cannot leave the company they decide to divorce. While trying to save Victor, Adam is shot at Victor's wedding in March 2013, and they mend their relationship by working together at Newman Enterprises. Chelsea discovers she is pregnant again, but tells Adam the child was fathered by Dylan McAvoy (Steve Burton). After Adam finds out Connor is his son, he plans to go for full custody, and plans to cut Chelsea out of Connor's life, believing she is an unfit mother. Victor and Adam's partnership at the company ends months later when it is revealed that Adam's silent partner in taking Newman Enterprises private again was Jack. When Victor announces Katherine Chancellor (Jeanne Cooper) left her company, Chancellor Industries, to him in her will, Adam leaves him all of his shares in the company and resigns. Shortly after, Adam suspects he may have struck Delia Abbott (Sophie Pollono) with his car while driving on a dark road. After Delia dies in the accident, investigations begin to find the driver, leaving Adam guilt-ridden. Chelsea moves in with him to help take care of Connor, and they eventually reunite.
After not telling anyone about hitting Delia, Adam fears the investigation is closing in on him. He names Jack Connor's godfather and makes him promise to protect him should anything happen to him, and then proposes to Chelsea again and asks her to move to Paris with him, like they had planned during their first marriage. At the same time, Victor's private investigation on the hit-and-run driver leads him to Adam. He agrees to not turn him in as long as he can take part in Connor's life; a role he had initially refused him. Adam agrees as he and Chelsea remarry. Days before their flight to Paris, Delia's father Billy Abbott (Billy Miller) puts the pieces together and realizes Adam is the one who killed his daughter. He holds him at gunpoint and demands he drive them to places where milestones in Delia's life occurred. While driving, Adam attempts to grab the gun as a shot is fired and the car drives off a ravine. One of them staggers away from the crash and collapses, revealed to be Billy. Nick and Paul Williams (Doug Davidson) find the overturned vehicle as it catches fire and explodes. Adam's body is thrown from the vehicle, is not recovered and he is presumed dead, devastating Chelsea just as news that Adam killed Delia breaks. However, Adam's bloody hand is later shown to be moving, alluding that he survived. Soon after, he is shown to be lying in a bed, being held captive by an unknown captor. Later Victor informs Chelsea that his investigators have found Adam's remains, but elsewhere Adam is seen paying off Victor's investigator, confirming that Adam has faked his death.
In November 2014, Adam is revealed to be recovering from multiple facial reconstruction surgeries, and is in the care of Sage Warner (Kelly Sullivan). When Adam is told of Chelsea and Billy's new relationship, he attempts to leave his current dwelling, with Sage assuring him that he is not ready and that any attempt to leave would only compromise the progress of the surgeries he'd recently had. Adam eventually recovers enough to have the bandages removed from his face; after the bandages are removed it is revealed that his face had been replaced by Gabriel Bingham; the man who died saving Adam's life, he returns to Genoa City with Sage, he comes across the people he knows, but none of them recognize Adam or get the feeling that they know him somehow. Adam, under the alias of Gabriel, would pose as being married to Sage, in a ruse to claim Gabe's inheritance from Constance, however, they would later divorce in April 2015. He would reconnect with Chelsea, whom he confessed his true identity, and would slowly begin to piece their life back together, with plans to relocate to Paris, until Victor stepped in to sue for custody of Connor, keeping them in Genoa City. In October 2015, Adam's true identity was revealed and would help Sage deliver his nephew in Chancellor Park, following a heated confrontation between the two. Adam would stand trial for his role in Delia's death. He was sentenced for ten years, and upon leaving the courthouse, was run over by an unknown assailant. Christine found out that the car is found at the south lake motel. The car was found out to be a rental and Kevin found a surveillance picture that showed that Chloe was behind the pedal to the metal. Adam regains consciousness after the surgery, and expresses no ill will towards Chloe.
Soaps In Depth reported that Engen quickly gained viewer support after joining the cast as Adam, as did the character's romance with Heather. The support continued when the character took a dark turn. Engen said, "To think there was any likability left in the character baffles me! I'm very grateful to the fans ... they've been so supportive." The actor said fans wanted Adam either redeemed or turned into a gray character. Davidson credited the character's likability to Engen's looks, saying, " ... he really nailed this character. Chris' all-American looks add another layer to this story: he looks like he regrets being so evil, but he can't help himself. When Chris informed me he was leaving, I told him he really accomplished something by being so likable playing this villain." Nelson Branco repeatedly praised Engen's acting and Adam's storyline with Ashley and Victor, saying, "[t]he Haunting of Ashley is fast becoming one of my favorite all-time soap storylines ever. It's so 1970s. I have no doubt former Another World master scribe and Paul Rauch BFF/frenemy, Harding Lemay, is freaking if he's watching this gothic, macabre and super-creepy mystery. Moreover, camp-ilicious Chris Engen (Adam) is stealing the story with his very bitchy, and sexy performance of a deranged son scorned." Soaps In Depth also commended Adam's storyline. The magazine awarded Engen a gold star for portraying Adam as a gray character with "sardonic humor". Soap Opera Digest named Engen "performer of the week" for his final scenes as Adam, saying the actor "gave a performance that elevated Adam from an average villain to a complex mastermind".
The story of Adam causing Ashley's miscarriage was named "editor's choice" by the magazine. Engen was nominated for a SoapCentral Award for Outstanding Supporting Actor in 2009. Some fans were upset that Adam and Rafe's "sex scene" was implied rather than shown onscreen; Branco spoke out about the issue, saying, "[f]ilming a sex scene between a straight and gay man could come off as offensive. Firstly, Adam would have to appear uncomfortable in the situation which could anger gay right groups, etc." Muhney also approved of the decision not to show the sex scene, saying, "[f]or me, the way it was done was tasteful and it almost makes the audience wonder what exactly happened. You can create that in your head and try to interpret it by how the characters reacted afterwards."
Muhney's performance in the role, has been met with critical acclaim, having garnered him his first nomination for the Daytime Emmy Award for Outstanding Lead Actor in a Drama Series in 2013. Branco referred to him "as the most-talked-about recast in Y&R history" and praised his debut performance on the show. Denette Wilford of TV Guide Canada also complimented the actor's portrayal of Adam, saying, "[v]iewers aren't supposed to empathize with him, but his portrayer managed to make it happen—a testament to Muhney." Michael Jensen of AfterElton.com wrote that viewers enjoyed the character as portrayed by Muhney. The actor said he received both positive and negative reviews from online fans. Paulette Cohn of About.com wrote that Adam was one of "daytime's best villains". Muhney's onscreen romance with Chelsea has received praise; Zap2it placed them at number three on their "Top 10 Soap Opera Couples of 2012" list. Writing for Music Times, Cate Meighan observed that Muhney's performance kept "longtime fans glued to their television", noting that ratings dropped following his exit.