Rick and Shane are described to be best friends since high school, and were employed as deputy sheriffs in King County, Georgia. Rick was shot and wounded during a gun battle with a band of escaped convicts, and left in a coma when the outbreak began. After awakening alone in the hospital, he is mistaken for a zombie and hit over the head with a shovel by Duane Jones. Duane's father Morgan takes Rick in and explains the zombie apocalypse to him. He sets off in search for his wife, Lori, and young son, Carl, and along the way discovers what has happened to the world.

Eventually, he meets up with a group of survivors who lead them to their campsite where Lori and Carl are, as well as Shane. They stay at the campsite for a few days, and within that time Rick's leadership grows and overpowers the authority Shane once had. He struggles with this responsibility however, attempting to weigh being fair and doing what he believes to be right, no matter what the rules of society were like in the past. He also finds himself butting heads frequently with Shane over the various decisions to be made. The group ultimately decides to move beyond the campsite once it proves to be insecure and leads to a large death toll, and move to the CDC in hope of finding a cure. The group unfortunately finds no answers at the organization, although the last remaining employee whispers a secret in Rick's ear.

In Season 2, after moving beyond the CDC following its destruction, Rick and company are trapped on the highway with a horde of walkers. His call for everyone to hide under the abandoned cars ultimately proves costly, as it results in Carol's daughter Sophia being chased into the woods by zombies. He attempts to rescue her, but loses her shortly after instructing her to hide leaving her alone to fight off her pursuers. Throughout the girl's absence, he questions his faith in God, and if the survivors can ever truly be safe.. While splitting up during the search, Carl is accidentally shot and the shooter, Otis, leads them to a nearby isolated farm. Rick is distraught over his son. He fights with the notion of whether humans are better off not living in the world. Carl miraculously pulls through after Shane retrieves supplies, which overjoys Rick.

Still, however, his perspective of his surroundings continues to alter, to the point where he gives up his sheriff attire and settles into more casual clothing, thus representing a significant transformation in his character. He frequently participates in search missions for Sophia, refusing to believe she is probably dead. He also attempts to reason with Hershel over letting the group stay with his family at the farm. His character becomes more nuanced after he is confronted with Sophia's death and reanimation, which reminds him of the hopeless and blunt reality of the world they are living in. While retrieving Hershel from a bar in town, he encounters two armed men who ask leading questions about Rick and his group. When Rick declines to answer, one of the men tries to shoot Rick. Rick shoots and kills them both. He and Lori take notice to Carl's increasing emotional hardness, and his relationship with Shane heads down a dark path, reaching boiling point when they are in conflict over the fate of Randall Culver, a teenage outsider.

It results in the two nearly killing each other in a brutal fight. To preserve the group's safety, he attempts to shoot Randall, but finds that he is not able to bring himself to do it. Shane prepares to kill Rick hours after Dale's death by killing Randall and during the search leading him out into the woods. Rick is able to talk him down; however, at the last second, he kills Shane with a single knife stab to the heart. He is distraught over Shane's death and witnesses his zombified friend get shot in the head and finally finished off by Carl. Following the events, Rick still shows great pain at the thought of losing Shane, but views his actions as justified, believing Shane was a genuine threat to the group. As the events begin to unravel to the other survivors, Rick confesses a long held secret he kept hidden from the group: that they are all infected (as discovered by Dr. Edwin Jenner of the CDC). Lori initially tries to console him, but then turns her back on him when she learns the horrifying truth to Shane's death. Confronting a group suspicious of his image and his leadership, Rick adopts a dark and tyrannical personality change, bluntly admitting that he killed Shane for good measure and later daring any would-be traitors to abandon the safety of the group.

In Season 3, following on nearly 8 months later, Rick is shown to have adapted a more ruthless style of leadership following the death of Shane. Throughout the winter, the group have been going around in a circle. While Rick and Daryl go hunting, they find an over-run prison facility. The group then take the prison's courtyard, and rest for the night. The next day, Rick, Daryl, Maggie, Glenn and T-Dog take the inner prison, and clear out some of the prison, making it a near safe heaven. They later go deeper into the prison, and get chased by walkers. Glenn and Maggie are separated, and whilst trying to find them, Hershel is bitten on the leg. After taking him to the seemingly abandoned cafeteria, Rick amputates his leg with his hatchet. Afterward, a group of human prisoners appear from behind the shutters. The prisoners are hostile at first to the group, and Lori suggests to Rick that she would fully understand and support him if he decided to kill them. Only two of the initial five prisoners supposedly survive during the clearance of a separate cell block for them and Rick seems glad to be rid of them. However, one other prisoner managed to escape walkers and jeopardized the safety of Rick's group by opening one of the gates to the main area of the group, which results in the death of T-Dog, and Lori's going into premature labor. Lori does not survive a C-section to save the baby, with Carl being the only available and willing person to prevent her reanimation. Devastated by the death of his wife, Rick goes berserk and reenters the prison, killing multiple walkers with only an axe and reaching the boiler room where Lori died. He discovers that she has been completely eaten by a nearby walker, which he kills and then begins to try and "dig" his wife's remains out of the creature. Rick then answers a series of successive phone calls from a nearby phone, each call leading him to believe that there are other survivors. He is shocked when they address him by his name, only to receive one final call from Lori, which helps him realize he is hallucinating and needs to snap back to reality.

Rick returns to the prison grounds, reconnecting with his son and the others. It is here when he sees Michonne walking towards the prison with baby formula. After a brief rescue of an exhausted Michonne, he learns from her that Glenn and Maggie are being held at Woodbury. He gathers Daryl, Oscar and Michonne and leads a party to rescue Glenn and Maggie. Right before he leaves, he shares a moment with Carl, and together, father and son name the newborn baby "Judith," after Carl's third grade teacher. Rick travels to Woodbury with the group, in hopes of reuniting with Glenn and Maggie. Rick and the group attack Woodbury, rescuing Maggie and Glenn; however, Oscar dies during their escape and Daryl is captured. Upon realizing that Daryl is absent, Rick immediately orchestrates a rescue operation, intercepting both Merle and Daryl, who were being forced to fight to the death by the Governor at the request of the citizens of Woodbury. Merle's presence among the group forms tension, especially among Glenn and Michonne, whom Merle had been ordered to kill. Rick and the group return to the prison a man short, as the threat of the Governor's impending retaliation looms large. Hershel, realizing reinforcements could help the group gain the upperhand, tries to convince Rick to take in Tyreese's group. However, just as it appears that Rick will concede, he begins to be haunted by the image of Lori, at which point he proceeds to have a mental breakdown. Tyreese's group flees the prison as Rick's sanity is called into question. His hallucinations of Lori continue and he begins to chase around the image of Lori both inside and beyond the prison's fences. Hershel, in an effort to restore some sort of stability in Rick's leadership, confronts Rick where he admits to seeing both Lori and Shane despite the fact that he knows they are both dead. Following the conversation between Rick and Hershel, the Governor attacks the prison, killing Axel and setting off dozens of walkers inside the prison in the process. Rick himself is pinned down by three walkers before being saved by both Daryl and Merle. Later Andrea, hoping to negotiate a truce between the two groups, visits the prison where she is met with a hostile response, especially from Rick. Rick asks Andrea to help the group sneak into Woodbury so they can kill the Governor themselves, which she refuses to do in part to the large number of innocents.

After learning of both Lori's and Shane's deaths, Andrea begins to understand why Rick is only a shadow of the noble, trusting leader he was in the past. Rick supplies Andrea with a car and a weapon on her way back to Woodbury, telling her to be careful. He decides to take both Carl and Michonne on a run for weapons and ammunition in preparation for the impending battle. They travel to Rick's old station where they find the armory to be completely removed of all weapons except a single bullet. Rick suggests they check local bars and restaurants as he signed off warrants for the weapons which belonged to the owners of those establishments. The group happens upon a strip of street rigged with booby traps where they are held at gunpoint by an armored gunman on a roof. Rick warns Carl to run back to the car as he opens fire; however, Carl remains and shoots the gunman saving his father's life. The gunman is revealed to be Morgan, the man who saved Rick's life in the pilot episode, who has clearly lost sight of who he was following the death of his son Duane. After attempting to kill Rick, Morgan snaps back into reality asking why Rick never kept his promise to communicate via the radio he had given him. Morgan tells Rick that he failed to kill his reanimated wife and that it was she who was responsible for Duane's death. He tells Rick there is little hope that he can keep Carl safe. Rick fails to convince Morgan to join the group, but he does salvage a bag of weapons. On their way back to the prison, Carl tells Rick that he likes Michonne, much to Rick's surprise. Michonne then confides in Rick, telling him that she knows he sees things and that she can relate to him as she used to talk to her dead boyfriend after the outbreak began.

Through the advice of Andrea, Rick attempts to negotiate with The Governor to prevent future violence. He proposes that the prison and Woodbury divide up their territory, which The Governor quickly rejects. The Governor tells Rick that he can prevent future deaths by turning over Michonne, who killed his walker daughter, Penny. When Rick returns to the prison, he tells the group that war is upon them. He secretly informs Hershel of The Governor's offer and asks him if he made the right decision. After The Governor massacres his army while on the side of the road after failing to take the prison, Rick, Daryl, and Michonne head out to confront The Governor. Along the way, they meet the lone survivor of the massacre, Karen. After discovering Andrea locked in a room after being captured by The Governor trying to escape from Woodbury, the group discovers she has been bitten. Andrea explains that she knows how the safety of Rick's revolver works, so the group waits while Andrea commits suicide with Michonne in the room. The next day, Rick brings the rest of the citizens of Woodbury to the prison and Andrea is buried in the front of the prison.

In Season 4, 6–7 months have passed since the group last saw the Governor. Rick has given up leadership of the now large group (around 40 survivors), and has taken up farming with Hershel, along with spending more time with Carl and Judith. He has regained much of his old personality, contrasting the cold, ruthless man he was in the third season. While Rick and Carl are gardening, they hear gunshots coming from the cell blocks, where Glenn informs them that walkers have invaded Cell Block D. Rick helps and kills many walkers, along with saving fellow survivors. Rick, Daryl, Hershel, former army medic Bob Stookey, and Dr. Caleb Subramanian, examine the body of survivor Patrick, who they believe started a sickness. While burying the bodies with Daryl, Maggie calls to them, telling them the fences are caving in due to the large number of walkers outside. Rick and Daryl use the piglets they have to lure the walkers away from the fences. Afterward, Rick gives Carl his gun back. Rick is next seen with Daryl, Carol, and Tyreese, examining the bodies of Karen and survivor David, who were killed and set on fire. Tyreese turns violent and attacks Rick, and Rick responds by brutally beating Tyreese's face, injuring his hand in the process. Rick begins investigating where Karen and David were killed, noticing a bloody hand-print that is smaller than his. He then sees Carol attempting to clean the water pipe, but she is becoming surrounded by walkers. He saves her, and tells her that it was stupid to go out there alone. He asks her if she killed Karen and David, to which she replies that she did.

Rick goes on a run with Carol to search for food. After arriving in a small suburb, they encounter two survivors who help them to search for food. Rick realizes that Carol is not showing remorse for killing two of their own. Later, when they attempt to find the two survivors, they find one dead and the other missing. Rick then banishes Carol from the group, giving her supplies and a car to fend for herself. Rick returns to the prison, where he tells Maggie and Hershel what happened with Carol. Rick enlists Carl to help him with the fences. Soon after, though, the fences break and a large number of walkers come through. Rick and Carl work together and dispatch them before they can get too far into the prison. Afterward, Daryl and his group return to the prison with the supplies needed to help the sick. The next day, Rick next tells Daryl about the banishment of Carol, and together they go to tell Tyreese. Before they can, however, the Governor appears with a large militia and a tank, bent on taking the prison for themselves. The Governor reveals that he has taken Hershel and Michonne hostage, who were out burning walker bodies. Rick attempts to negotiate with the Governor, telling him that they can all live in the prison together in peace. The Governor, however, calls him a liar and decapitates Hershel. A gunfight breaks out immediately, and Rick is shot in the thigh while retreating back to the group. As the militia drives the tank through the fences and into the prison, Rick confronts the Governor and fights him. However, due to his multiple injuries, the Governor gains the upper hand. Just before Rick can be strangled, Michonne appears and stabs the Governor through the chest with her katana. Rick goes to the prison courtyard and is reunited with Carl, and together they find Judith's empty and bloody baby carrier. They both begin to weep, but Rick realizes they must leave the prison. The two are separated from the rest of the group (just as everyone in the group has been separated into multiple smaller groups), and Rick tells Carl not to look back at the destroyed prison behind them.

After the prison attack, Rick and Carl hole up in a house in a neighborhood that they found. Carl begins scolding him saying The Governor knew where they were and all Rick wanted to do was plant vegetables and hide. He goes on to claim that he didn't forget his skills to survive and that he can survive without Rick. Carl later lures two walkers away from the house to kill them somewhere else so he wouldn't attract noise. After a skirmish with more walkers, Carl returns to the house and upon seeing Rick rise from a couch they used to block the door from walkers, thinks Rick is dead and aims Rick's own revolver at him. Now realizing that he needs Rick, he says he is scared. Rick and Carl later talk near the couch the next day and a knock is heard at the door. It is revealed to be Michonne and Rick says it's for Carl. While Carl and Michonne are on a supply run, Rick lies in bed upstairs and hears a scavenger group enter the house. Startled, he hides under the bed and watches one member choke another member into unconsciousness after fighting over the bed. He slowly sneaks into the bathroom to discover another member and strangles him to death. After leaping from the roof, he sees Carl and Michonne return from their supply run and tries to kill one member eating something to prevent him from discovering Carl and Michonne. Luckily for Rick, the man he kills in the bathroom earlier reanimates and gunfire erupts, prompting the man to go inside the house. He then runs towards Carl and Michonne and they leave the neighborhood. They see a sign on a train car that describes a place called "Terminus". They head towards "Terminus". While walking, Carl and Michonne do a dare where they walk on the tracks and the person who loses his/her balance doesn't get the chocolate bar they're having. Carl wins and eats the chocolate bar. He drops it on the tracks as they continue the walk. The chocolate bar is later found by the marauders Daryl was with on the way to Terminus.

Rick, Michonne, and Carl struggle to find food and shelter. The group of men led by Joe that Daryl has been traveling with find Rick and make known their intent to kill Rick for strangling their friend. They hold Michonne hostage, attempt to sexually assault Carl, and start to beat Darryl for trying to intervene and sacrifice himself. Rick fights off Joe and kills him by gruesomely biting his neck, as well as saving Carl from his attacker by stabbing him repeatedly in front of Carl. The group then make their way to Terminus and are met by the inhabitants after sneaking in. Not long after, a conflict ensues after the survivors notice that the inhabitants are wearing gear and articles of clothing that belonged to Glenn, Maggie, and other survivors they knew. The citizens of Terminus trap the group in a boxcar, where they find their friends, plus some new people, are there. The episode ends with Rick telling the others that the people at Terminus are "screwing with the wrong people."