Jim is characterized professionally by his success and apathy towards his work, his pranks, and his geniality with his co-workers. Even at the outset of the show, Jim has worked at Dunder-Mifflin some years, and the character is eventually promoted to the point of assistant regional manager, one post below the character Michael Scott. In the episode "Office Olympics", he mentions closing two sales during his lunch break. He also won an award for being the ninth best salesman in the company that year, with Dwight taking top honors ("Dwight's Speech"). However his professional success contrasts sharply with his discontent and apathy. Despite his years of working at Dunder Mifflin, Jim insists the job is a temporary one, saying, "If I advance any higher, this would be my career. And if this were my career, I'd have to throw myself in front of a train." This outlook is most apparent in the elaborate pranks that he plays on his workmates, primarily Dwight, as well as his sarcastic remarks and facial-expressions to the film crew and his provoking comments during often ridiculous employee meetings. Dwight has filed innumerable formal complaints again Jim for the pranks. While typically ignored, or even encouraged, by co-workers and even his boss Michael, these pranks have backfired on Jim on occasion; in the episode "Conflict Resolution," upon finding out his innumerable complaints were never actually sent to the "special file" at Corporate he demands that Michael either fire Jim or transfer him out of the Scranton office. In the episode "Goodbye, Toby", then-VP Ryan Howard issues Jim a formal warning for lack of "productivity".
Despite his mischievous streak, he often shows compassion to and camaraderie with his co-workers. Dwight asserts that Jim is a friend of the delivery man Steve ("Booze Cruise"); Sadiq, the company IT guy, attends a barbecue at Jim's house ("Email Surveillance"); and Jim quickly bonds with Kevin's fiancée's daughter on "Take Your Daughter to Work Day". David Wallace, the CFO of the company, remarks that Jim makes a good impression on everyone he meets. In Season 4, Jim, upon urgent looks from Pam, consoles Dwight after his difficult breakup with Angela in "Money," and, to the same end, even patronizes Dwight's unsuccessful bed and breakfast, later writing a good online review about it. When an uninvited Michael crashes his party and sings karaoke in yet another painfully awkward attention-hogging moment, Jim saves him from humiliation by joining in ("Email Surveillance"). When a dejected Jim considers giving up on Pam following her acceptance of Roy's marriage proposal, it is Michael he confides in. In turn, Michael encourages him to "never ever ever give up", which encourages Jim to talk with Pam in the episode "Casino Night". When Jim relocates to another branch, Michael is hurt, assuming Jim left because he did consider Michael as a good boss or friend. While visiting Michael's hotel room during a business conference, Jim assures Michael that he considers Michael a friend and "a great boss", and confesses that he left because of Pam.
He is revealed to be responsible, though somewhat of a loner, in his private life. While in Scranton, Pennsylvania, Jim rented a house with a roommate, Mark. Jim admitted to Pam that he did not have much of a social life, staying home and watching TV most nights, a fact that both Pam and Jim have made fun of on different occasions. He enjoys cycling ("Email Surveillance," deleted scene; "Fun Run") and sometimes babysits Toby's daughter Sasha ("Take Your Daughter to Work Day," deleted scene).
From this point, Jim develops a seemingly unsteady attitude toward Pam's impending nuptials. On the one hand, he asks out Brenda, a corporate office employee who came along for the Booze Cruise; he also tells Kelly that if the guy she has a crush on doesn't like her, she should just forget about it and move on, indicating that he has done the same. On the other hand, he gets upset when he sees Pam and Roy eating lunch together, and most tellingly, becomes so depressed hearing Pam discuss the wedding that he calls a travel agency and schedules a trip to Australia, deliberately making himself unable to attend the wedding.
Feeling bored by work, guilty about a stack of complaints that Dwight has made about him, and tortured by his situation with Pam, Jim investigates a transfer to Dunder Mifflin's branch in Stamford, Connecticut. After Jan confirms that he's gotten the transfer, Jim confesses his love for Pam in the season two finale "Casino Night". Pam, whose wedding to Roy is all planned out and just weeks away, clearly shows her anguish but gently turns him down, yet he returns to kiss her minutes later. We learn at the start of season three that both of them had wanted to kiss for quite a long time, but Pam again told Jim of her intentions to go ahead with the wedding.
When Jim meets up with Michael at a paper distributors' convention, he tells Michael that he considers him a "great boss" and admits that he only transferred because Pam rejected him. Jim has learned that Pam called off her wedding, but chooses to remain in Stamford. Things begin to look up for Jim as he befriends salesperson Karen Filippelli, and when the company board of directors decides to close the Scranton branch, Jim is named Assistant Regional Manager of the newly created "Dunder Mifflin Northeast". However the company's plans change when Stamford regional manager Josh Porter accepts a job at Staples. The Stamford branch then closes, with a few employees being offered a transfer to Scranton. The offer to Jim to be Assistant Regional Manager stands, though now at Scranton. Jim is disgusted by Josh's disloyalty, saying in an interview: "Say what you will about Michael Scott, but he would never do that." Jim is at first unwilling to return to Scranton because of Pam but eventually decides to do so. Karen, who has grown fond of Jim and wishes to pursue a relationship with him, also transfers to Scranton.
In Scranton, Jim's and Pam's reunion is awkward. Pam is overjoyed, but Jim is clearly uncomfortable. He lets Pam know that he is seeing someone, and gradually Karen is introduced as his girlfriend.
As Jim settles back in at Scranton, he uses his promotion as an excuse to avoid his old interactions and pranks with Pam, claiming that pulling pranks are not appropriate for his position. However, in time, Jim does returns to his old ways, especially targeting Andy Bernard, a Stamford transfer, and Dwight. However, the relationship between Jim and Dwight seems to improve slightly.
Toward the middle of the season it becomes clear that Jim's unresolved feelings toward Pam are affecting his relationship with Karen. Jim discourages Karen from moving out of the hotel in Scranton where she has been living since the merger and into a house two blocks away from his own because as he says, "it would be like we were living together." Jim only relents when Pam tells him he is being unreasonable. Even so, Pam is seen crying over seeing Jim and Karen move forward in their relationship. Karen, who had previously been oblivious to Jim and Pam's history, accidentally learns of Jim's feelings for Pam during a sales call with Phyllis. Karen then confronts Jim about it over coffee. Jim assures Karen that he is really happy with his new relationship.
During a busy day, Jim decides to pull a prank on Andy; however, Karen is unable and Ryan unwilling to aid him, so he turns to Pam, who readily agrees. Their interaction during the prank causes Karen to feel threatened. She again confronts Jim, and this time he admits to still having feelings for Pam. Karen and Jim struggle to maintain their relationship, and although in Phyllis' Wedding, Jim hints that he would be interested if, hypothetically, Pam were interested in him, Jim then sees Pam leave the reception hand in hand with Roy, and declares, "Here's a non-hypothetical. I'm really happy I'm with Karen."
In "Cocktails", Roy trashes the bar when Pam tells him she kissed Jim during "Casino Night." Roy then attempts to attack Jim at work in "The Negotiation", but Dwight sprays Roy with pepper spray. Roy is fired, but when Pam assures Jim that it is over between her and Roy for good, Jim doesn't believe it and tells her so. Jim tries different ways to thank Dwight for saving him only to have each attempt rejected. When Jim catches Dwight and Angela kissing in the office, he tells the camera crew he will not tell anyone about it as repayment.
Jim and Pam's relationship becomes tense again in "Beach Games" when on a company outing at the beach, Pam confesses to Jim in front of everyone that he was the reason she broke off her wedding to Roy. She also states that she has missed their friendship since he left Scranton for Stamford. Later that night, Jim tells Pam that he feels as if he never really came back from Stamford, tacitly admitting that he has actively been fighting his feelings for her all year. However, Jim's relationship with Karen and pending interview for a corporate position which would require his relocation to New York City, still obstruct a potential romance.
In The Job, Jim, Karen and Michael each interview for the corporate position. During the interview he notices an affectionate note from Pam. After the interview he drives back to Scranton, leaving Karen without a ride. Jim interrupts an interview with Pam to ask her to dinner, and after she accepts, he says "All right. Then... it's a date." In a webisode titled "Office Summer Vacation," found on NBC's website, Karen states that Jim "dumped her ass" and left her crying at a fountain.
Pam and Jim initially attempt to keep their relationship status a secret from their office co-workers as well as the documentary camera crew, but when the camera crew catch them together sharing a quick kiss while parked on the side of the street, they admit that they have been dating for a few months and are very happy ("Fun Run"). In the episode "Dunder Mifflin Infinity", Toby reveals that Jim and Pam are dating to the office when he sees Pam kiss Jim on the cheek. The pair's union is welcomed by most people in the office, except Dwight who says both "could do better."
Michael takes interest in the relationship and repeatedly invites the couple for dinner with him and Jan, but Jim finds reasons to avoid accepting the invite, though he and Pam avoid making Michael suspicious of their disinterest by asking to have dinner on nights when Michael is busy. They eventually are forced to join Michael and Jan for a dinner party when Michael feigns an assignment from corporate to get them out of any original plans they might have had. At the dinner party, Jim and Pam are forced to witness various aspects of Michael's and Jan's deteriorating relationship to the point where they make a desperate but failed attempt to escape. Jim even attempts to escape without Pam after he couldn't get her out with him, but Pam gets him to stay. After witnessing the break up of Michael and Jan, Jim and Pam enjoy burgers in his car and they appear to be the happiest and most stable of the three couples that attended the party, the third couple being Andy and Angela.
Jim and Pam feel sorry for Dwight, whom Angela dumped for Andy. To cheer him up, they spend a night together at his Schrute's farm, which doubles as an agricultural bed and breakfast. Jim realizes that the trip is his and Pam's first night away together and comments that he had always imagined it in his head but that he always thought it would be different. They write a glowing review on TripAdvisor about their stay, however, to help bring Dwight out of his depression, but are unsuccessful. Jim comforts Dwight in the stairwell, explaining how he used to pine for Pam and how he was deeply hurt in Season 2 when Pam decided to stay with Roy, saying that it was not something he would wish on the worst of his enemies. After remembering how terrible he had felt before he was with Pam, Jim kisses her publicly. Pam attributes this to a passion for Italian food, which Jim confirms and says that he is "in love with Italian food", implying he is in love with Pam. Afterwards, when Dwight returns from the stairwell, he returns to his normal self, which pleases both Jim and Pam.
Jim has a Second Life avatar, that resembles him ("Local Ad"), but there are some differences, as Pam teasingly points out that his online alter-ego plays guitar and is a Philadelphia sports writer. In the episode "Survivor Man", we see Jim in a manager role while Michael is out of the Office. Jim attempts to combine all of the birthday parties into one big party, to save time. After being accidentally called 'Michael' instead of 'Jim', Jim realizes that he has done something Michael would have normally done. In a conversation with Michael at the end of episode, Michael reveals that he did in fact try to combine all the birthday parties earlier in his time as regional manager. We see Jim in a manager role again in "Night Out" when he plans to save everyone else from coming into work on Saturday to help with Ryan's website by staying late to do the work, a plan that is met with success until they find the gate locked with them still inside. Everyone else gets mad at him for not informing the guard of his plan.
In the episode "Chair Model", Jim invites Pam to move in with him, as she's looking for a new apartment; she explains she would only live with someone she was engaged to. Jim comically tells an incredulous Pam that he will soon propose; and then reveals to the camera crew a diamond ring, explaining that "[he] got it the week after [they] started dating". As he and Pam are leaving work, he gets down on one knee and looks at her expectantly, only to ask her to wait while he ties his shoe. In "Did I Stutter?", Jim pulls another faux proposal on Pam by "proposing" that she get him a coffee.
In the same episode, he receives a performance warning from Ryan, who cites "goofing off with Dwight" and "spending time at reception" as productivity problems. Toby (jealous of Jim and Pam's relationship) concurs. Jim counters that Ryan's accusations are due to Jim's critical comments to David Wallace about Ran's website initiative, though Ryan denies it. A shocked Jim returns to his desk and decides not to tell Pam what happened, though she can clearly see that something is bothering him.In a deleted scene, Jim is seen talking with Toby about the warning, where Toby informs that Ryan has used Dwight's complaints as a reason to attack Jim's productivity, though Toby agrees with the fact that Jim has good sales numbers. Ryan is then seen confirming the fact that he is going after Jim, despite and because of his popularity with Ryan's boss.
In "Job Fair", Jim decides to meet up with a potential client after Ryan gave him his formal warning, as he wishes to keep his job to secure "pretty big long term plans" with Pam. He goes with Andy and Kevin to meet the client on the golf course. Jim is made uncomfortable with Andy making jokes in front of the client and Kevin trying to force him into a wager. Jim tries to talk business with the client, but the client only accepted Jim's invitation just to get out of the office. After several unsuccessful attempts to get the client to sign with him, Jim holds him in the parking lot for fifteen minutes until the client finally gives in. Back at the office, when Pam returns from the job fair, Jim gives her the news and they share a congratulatory kiss in front of Michael, Andy, and Kevin. Once they realize Michael, Andy, Kevin, and the cameras are watching, Pam stops and shakes Jim's hand. Jim responds "You know what? Screw this." and passionately kisses her again.
In "Goodbye, Toby", Jim shows his happiness and support for Pam getting into the Pratt Institute, where she will be for the next three months. Jim gets so frustrated over Ryan's consistent attempts to get him out of Dunder Mifflin that he decides to leave a message on Ryan's phone proclaiming he is not going anywhere. Later, Jim discovers a video on YouTube showing Ryan being taken out by police for fraud, after which Jim leaves another message on his phone making a joke about his arrest. Michael asks Jim for help on wooing the new HR rep, Holly. Michael wants to rush their new, potential relationship, but Jim tells him to take it slow and begins to recount his story about how he fell in love with Pam. Inspired by this, Jim reveals that he is going to propose to Pam during Toby's goodbye party. He pays Phyllis money to buy fireworks to set the mood for his proposal. While the fireworks are set off, Jim, sitting next to Pam, pulls out the ring and is about to propose until Andy proposes in front of everybody to Angela, who accepts. Jim puts his ring back in his pocket and postpones the engagement, which disappoints Pam, as she thought he was going to propose.
|Episode no.||Episode title||Prank||Notes|
|1||"Pilot"||Encased Dwight's stapler in Jell-O.||These pranks (and the entire episode) were largely taken from the pilot episode of the original series|
|Built a pencil fence between his and Dwight's desk.|
|Encased Michael's 'World's Best Boss' coffee mug in Jell-O. ("Pilot")|
|"Diversity Day"||Changed Dwight's assigned "race" from "Asian" to "Dwight" in the Diversity Day exercise.||deleted scene|
|"Health Care"||Locked Dwight inside his own "work space".|
|Assisted Pam in preparing a list of absurd medical conditions.|
|"The Alliance"||Agreed to participate in an "alliance" with Dwight, using it to feed his paranoia in a variety of ways including dyeing his hair and hiding him in a box.|
|"Hot Girl"||Convinced Dwight to purchase a purse from a vendor and then made fun of him for having it|
|"Office Olympics"||Found Dwight's wallet in the parking lot, and decided, on Pam's suggestion, to give the wallet back to Dwight intact and unchanged. Dwight, not believing Jim, immediately canceled all his credit cards.||deleted scene|
|Threw stuff in Dwight's coffee mug.|
|"Halloween"||With Pam, posted Dwight's résumé online, specifically for positions in Alaska.|
|"The Fight"||Relocated Dwight's desk to the men's restroom.|
|Stole Dwight's purple karate belt.|
|"Performance Review"||Popped Dwight's fitness orb.|
|Convinced Dwight a Thursday was a Friday, causing him to be late for work the next day.|
|"E-mail Surveillance"||Made Dwight believe that Jim's party was a surprise party for Michael. This prank backfired when Michael crashed the party.|
|"Booze Cruise"||Placed Dwight's wallet and desk items in the vending machine. Following this, he hands Dwight a bag of nickels, probably just removed from his phone handset.|
|"Dwight's Speech"||Gave Dwight dubious "tips" on public speaking.|
|"Drug Testing"||Tried to convince Dwight in an interview that Dwight had smoked marijuana.|
|"Conflict Resolution"||Paid coworkers five dollars to call Dwight "Dwayne" for an entire day.||These pranks were mentioned but were not seen on camera. The police tape prank was mentioned in a deleted scene.|
|Convinced Dwight an abandoned infant was in the women's restroom, causing him to walk in on Meredith "on the can."|
|Used a macro so that every time Dwight typed his name, it appeared as "diapers."|
|Replaced Dwight's writing instruments with crayons|
|Incrementally increased the weight of Dwight's telephone handset with nickels, then abruptly decreased the weight, causing Dwight to smack himself in the face with the phone|
|Placed a bloody glove in Dwight's desk and attempted to convince him that he had committed murder. Dwight, in fact, thought that "Jim was the real killer|
|Created an absurdly large identification badge for Dwight that labeled him as a security threat, and said that his middle name was Fart|
|Repositioned Dwight's desk by moving it an inch at a time over the course of the day|
|Encircled Dwight's desk in police tape|
|"Casino Night"||With Pam, convinced Dwight that he (Jim) had telekinetic powers|
|"Casino Night"||Inadvertently caused Dwight to fold in Texas Hold Em whenever he (Jim) coughed as Dwight believed this was Jim's tell that he had good cards|
|N/A||N/A||Held Dwight's bobblehead doll for $5 ransom||This prank appeared in a primetime preview of the Third Season premiere|
|"Gay Witch Hunt"||Convinced Dwight (and Michael) that gaydar was a real electronic device; later sent Dwight a doctored metal detector ;||The detector's alarm sounded in front of Oscar's belt buckle (crotch area), convincing Dwight that it worked. It then went off on his own, causing him to fear that he himself was gay.|
|Gained access to Dwight's hotel room at a paper convention in Philadelphia.||Upon entry, he caught a glimpse of a naked woman on the bed before fleeing; he assumed she was a prostitute. It was actually Angela Martin.|
|"Gay Witch Hunt"||Encased Andy's calculator in Jell-O|
|"The Coup"||With Pam, made high-pitched noises hoping Dwight would schedule an appointment with an ear doctor, called "pretendonitis"||This prank was mentioned, but was not seen on camera.|
|A number of ploys for finding Herr's chips for Karen, including imitating a man from the warehouse|
|With Karen, replaced Andy's good chair with his squeaky one|
|"Branch Closing"||Sent faxes to Dwight signed "Future Dwight" on Dwight's own stationery|
|"The Merger"||Stared at Dwight's forehead for no reason|
|"The Convict"||Gave Andy wildly incorrect "tips" on winning Pam's affections.||Pam did the same to Jim in a deleted scene|
|"The Convict"||Ordered fifteen large sausage pizzas to the office under the name "Dwight"||deleted scene|
|"A Benihana Christmas"||With Pam, tricked Dwight into believing he was being recruited by the CIA and made him destroy his cell phone|
|"A Benihana Christmas"||Told Dwight that their waitress could not remember how to butcher a goose, causing Dwight to tell her how to in violent detail||The restaurant was very noisy, and Dwight was at the far end of a table that they were sharing with an unknown couple. When Dwight would ask what was going on, Jim would give misdleading answers.|
|Told Dwight that the Benihana Waitress was asleep when really Andy was telling her to close her eyes and imagine her dream home. ("A Benihana Christmas")|
|"Back from Vacation"||Expression shock at Dwight's absurd behavior when Dwight taped a meeting, though of course, Dwight was doing nothing|
|Glued Dwight's office drawers together||deleted scene, mentioned but not seen on camera|
|Changed Dwight's voicemail to make him sound like a chipmunk||deleted scene; mentioned but not seen on camera|
|Told Dwight there was a 4am meeting, who was the only one to attend.||deleted scene; mentioned but not seen on camera|
|Shipped Dwight's desk by mail to Roswell, New Mexico, where Dwight was vacationing||deleted scene, mentioned but not seen on camera|
|"The Return"||Hid Andy's cell phone in the ceiling tiles over his head, then, with Pam, called it repeatedly ()||Andy became so angry he punched his fist into a wall. His character was then sent to anger management and was absent from several episodes.|
|"Ben Franklin"||Hired a Benjamin Franklin impersonator instead of a male stripper for Phyllis's bachelorette party|
|"Ben Franklin"||Told Dwight that the Ben Franklin impersonator was the real Franklin|
|"Phyllis' Wedding"||Use pavlovian classical conditional to cause Dwight to expect an Altoid mint each time he heard Jim's computer reboot|
|"Phyllis' Wedding"||Manipulated Dwight into patrolling for wedding crashers||Dwight mistakingly bounced an invited guest who to suffered from dementia and was unable to answer questions about the groom|
|"Business School"||Convinced Dwight that he (Jim) was turning into a vampire|
|"Cocktails"||Hid the key to Michael's straitjacket|
|"Safety Training"||Relayed intentionally incorrect messages from Dwight to Andy when Dwight was "shunning" his traitorous co-worker|