The creators of the series acknowledge that Rimmer's surname comes from a snobby prefect with whom they attended school. They claim, however, that only the boy's name was used, and not his personality.
At the age of 14, Rimmer divorced his parents and left home. Despite his loathing of his father, Rimmer nevertheless felt a perverse desire to vicariously live out his dream. As such, Rimmer joined the Space Corps at a low-entry level as a third technician, and devoted his life to his career, engaging with few activities outside of work. On one notable occasion, he volunteered for the Samaritans, a suicide-prevention helpline, only to resign after one day when five people committed suicide after talking to him — one of whom had dialed the wrong number and only wanted the cricket results — an event dubbed "Lemming Sunday" by the newspapers. (A similar event occurs in the life of another Chris Barrie character, Gordon Brittas, this time called "Black Friday".) Sometime during his life, Rimmer also earned two swimming certificates: one Bronze Swimming Certificate, and one Silver Swimming Certificate — BSc and SSc respectively — to which he often makes reference to on his official correspondence in lieu of any actual qualifications (it is alluded to later in the series that Rimmer cannot swim, thus making his possession of these certificates something of a mystery). He is also rather unsuccessful with women, managing to have a sexual relationship with only one woman, Yvonne McGruder, the ship's female boxing champion (who was apparently concussed at the time, a fact that Dave Lister never fails to point out). The entire encounter lasted little more than twelve minutes, including the time it took to eat a pizza. This is later contradicted when Rimmer claims that he lost his virginity in the back of his brother's Bentley with a girl named Sandra.
Rimmer's deepest ambition is to become an officer in the Space Corps, but his career is little more distinguished than his previous efforts. Despite serving in the Space Corps for fourteen years, he only managed to further himself from third technician (the lowest rank on the ship) to second technician (the second-lowest rank on the ship), and the only medals he ever received were for his long service to the Space Corps, awarded to him every three years. His attempts to further himself usually end in failure; he took the astronavigation exam no less than 13 times without success, despite his efforts to study and / or cheat. In one case, he reportedly wrote "I am a fish" on the answer sheet four hundred times before performing "a funny little dance" and fainting. He was also invited to the captain's table once in his entire career, only to humiliate himself when served gazpacho, which he demanded be taken away and brought back hot, to the amusement of everyone else present. He blames this faux pas for the stagnation of his career (rather than the more obvious culprits, namely his personality and incompetence) and never forgives himself — his last words before he dies are "gazpacho soup". He also leads a campaign to replace the standard Space Corps salute with an extremely elaborate one of his own design, which fails when absolutely no officers display any interest at all.
During his service on Red Dwarf, he is assigned to both work with and share quarters with Third Technician Dave Lister, his only inferior in rank on the ship, for whom he instantly develops a warm and reciprocated loathing. The two are notably different in personality — unlike the uptight and pompous Rimmer, Lister is unmotivated, slovenly, relaxed and well-liked — and they clash often.
The series contradicts itself on how Rimmer died, and, consequently, how the radiation leak came about. In Series I, Rimmer is alleged to have failed to repair the drive plate properly, and blames Lister for his death because it was "a two man job". A video of Rimmer's death seen in "Me²" supports this version of events, showing the captain of Red Dwarf berating Rimmer for doing sloppy work on the drive plate at the time of the explosion. In later series and in the Red Dwarf novels, however, some fans question the fact that Rimmer's rank was too low and his abilities too lacking for him to have been plausibly assigned the responsibility of repairing the drive plate; consequently, in Series IV Episode 3, "Justice", the story suggests that Rimmer's sense of responsibility for the disaster is due to his zealous egomania and that he could not possibly have been responsible for the accident. This is reinforced by the novel, Infinity Welcomes Careful Drivers, in which the radiation leak is due to a complex chain reaction (including a reactor technician spilling coffee all over his control panel), in which Rimmer plays no part, having just woken up after fainting during his exam. However, Grant Naylor has not specified which canon is correct; it is left open to speculation. Many believe that Rimmer was responsible as per series VIII, when the newly resurrected Rimmer handing over a report to the captain regarding the drive plates (with information that Lister had given him): he tells the captain that he fears a faulty plate could cause a radiation leak. He goes on to say that, anyone who mis-repaired a drive plate would have to have "a brain the size of a leprechaun's testicle". Thus this little gag reinforces the former story, that Rimmer did indeed have responsibility for the disaster. A possible reconciliation of the various TV show versions is that Rimmer did, indeed, misrepair the drive plate, but that the "Justice" computer held the command staff ultimately responsible for assigning a job with such potential for devastation to a technician with a record as tarnished as Rimmer's.
As a "soft-light" hologram, Rimmer retains his memories and physical appearance, but is composed almost entirely of light and has no tangible form (other than a small "light bee" projection unit that hovers within his apparent form). Although he didn't exactly use his body to its fullest during his lifetime, he finds himself missing it after his death. While a soft-light hologram, he could lay down or sit in his bed. He remains very unhappy with his lot for several years after his death, and frequently and loudly bemoans his fate — he is keenly aware that the "real" Arnold Rimmer is long dead, and his current sensibility is just a computer simulation of how he would feel if he were alive. Despite his dissatisfaction with his existence, he bitterly resists any move to turn him off, and attempts to improve himself intellectually and in career with little more success than he had during his life. At one point, after attempting to use time-travel in order to establish himself as the multi-millionaire creator of "tension sheets", he is briefly returned to life — however, he accidentally triggers an explosion that sees him quickly restored to being a hologram once again. He remains as obnoxious and difficult to like for his crewmates as he was before his death, and gradually develops a pompous tendency to quote Space Corps regulations at any possible opportunity; he usually gets them wrong, however, and the regulation he has quoted is frequently one that has no relevance whatsoever to the situation at hand.
After some time spent as a "soft light" hologram, the Red Dwarf crew — having lost Red Dwarf and reduced to living on Starbug — encounters a being known as Legion, who upgrades Rimmer's projection unit from "soft light" to "hard light", giving him a physical form and the ability to interact directly with the world, in addition to making him virtually indestructible. To conserve power (more of which is required for Rimmer's hard-light hologram) he normally uses soft light, only switching to hard light when necessary. This return to tangibility appears to improve Rimmer's personality; although still cowardly, pompous and neurotic, he is shown to be more capable of acts of bravery and nobility (such as in "Out of Time", when he agrees with his crewmates that should they fight their corrupted future selves who have a highly improved JMC Starbug rather than backing down, saying "Better dead than smeg.").
Soon after his conversion to hard-light status, Rimmer is approached by a dying alternate version of himself, Ace Rimmer (see below), who asks Rimmer to become a defender of the multiverse upon Ace's death. Although initially hesitant, Rimmer finds himself rising to the challenge, and after a moving send-off from his crewmates (in which he is retroactively promoted to First Officer by Lister for managing to keep him sane), Rimmer leaves to start his new life.
Initially, Lister misses his old sparring partner and is briefly convinced that he had actually liked Rimmer. However, a virtual reality amusement park called "The Rimmer Experience" based on Rimmer's diaries — in which Rimmer had interpreted events in order to present himself as a fearless hero saving his incompetent crewmates, complete with a flattering song sung by a chorus of Rimmer puppets — soon reminds Lister of just how obnoxious Rimmer had been (see episode "Blue") and convinces him that his nostalgia was misplaced.
This version of Rimmer, however, soon loosens up once in prison. Unlike his predecessor, this Rimmer wasn't as dedicated to the Space Corps. Although still dreaming of being in command, he doesn't seem to worry about protocol (although he does worry about getting in trouble). He seems to have a better relationship with the Dwarfers, joining in willingly on pranks and going on ventures with them. He's also less inclined to try and take charge of a situation.
At the end of Series VIII, when a chameleonic microbe destroys Red Dwarf and everyone else evacuates to a mirror universe, Rimmer is trapped on the disintegrating ship. His fate is currently unknown, but at the end of the episode he encounters the Grim Reaper and knees him in the groin, saying, "Only the good die young," indicating that he may very well survive. However, with no new episodes of Red Dwarf being broadcast since 1999, no resolution has been achieved, yet.
Fond of war, at least in principle, Rimmer dreams of being a general. He admires power and strength, and his role models included Napoleon Bonaparte, Adolf Hitler, and George Patton. He puts this down to being the reincarnation of Alexander the Great's chief eunuch, which he believes also explains his fear of nutcrackers and, according to Lister, why he is such a good singer. However, while still alive, his martial dreams never progress beyond playing Risk, because he is a complete physical coward, more likely to flee from any situation involving danger. As a hologram, Rimmer was finally able to live his dream of commanding an army in the Series IV episode "Meltdown", leading an army of "hero" wax-droids against "villain" wax-droids. Unsurprisingly, given his disdain for the lives of his own soldiers and congenital incompetence in general, this results in a less than perfect result. It should also be noted that, according to Kryten, Rimmer is even more deranged than usual in this episode due to Lister's having chewed his light bee. Ultimately, those of Rimmer's wax-droid soldiers that don't melt due to his brutal training regimen are instead massacred as part of Rimmer's battle plan, "a daylight charge over the minefield - it's the last thing they'll be expecting!" Although Rimmer ultimately succeeds in destroying the entire "villain" army, his own army is wiped out completely. Disgusted with Rimmer's cavalier attitude towards having destroyed the entire population of a planet, Lister swallows his light bee. The hologrammatic Rimmer's obsessions with Risk and military conquest are never substantively discussed again. In addition to his fondness for militarism and Hammond organ music, Rimmer also enjoys Morris dancing and is an authority on 20th century telegraph poles, especially those observed while train spotting.
Many episodes of Red Dwarf focus on the conflict between Rimmer's ego and his neuroses. In "Me²", Rimmer manages to trick Lister into generating a holograph duplicate in order to provide him with a companion; however, as a consequence of Rimmer's self-loathing, the two Rimmers are incapable of getting along, and their interaction becomes so bitter and hate-filled that the duplicate must be turned off. In "Terrorform", a "psi-moon" sculpted to reflect Rimmer's psychological make-up becomes a desolate, swampy hell-hole dominated by Rimmer's Self-Loathing, personified as a sadistic beast, with a metaphysical graveyard marking the "demise" of his various virtuous qualities.
However, it is also shown that Rimmer's personality flaws are not irrevocable, and are in fact almost completely a result of his hang-ups. The most obvious example of this is Ace Rimmer, an alternative version of himself who is kept back a year in school instead of being allowed to pass (as was the case with the "proper" Rimmer), and as a result learns humility and inner strength, growing up to become a charming and well-liked Space Corps test pilot, interstellar hero, and sexual seducer (see episode "Dimension Jump"). Rimmer immediately hates his alternative self, bitterly resenting the proof of what he could have achieved had he only received the "break" his alternative self got (the irony being that, by Rimmer's terms, he did get the break).
On top of this, it is also established that the "proper" Rimmer is not incapable of nobility and honour. When Red Dwarf encounters a Holoship, with an all-hologram crew composed of the "best and brightest", Rimmer can interact as if he were alive again, so naturally he cheats on a test to become a member of the crew. A female officer aboard the ship, Nirvanah Crane, explains that because they were all holograms and had zero chance of pregnancy or transmitting sexual disease, the holo-crew's R&R hours consists of near-constant casual sex, with as many partners as you wanted over time with no emotional strings attached. Rimmer and Crane fall in love, and Crane sacrifices her place on the ship for Rimmer, only for Rimmer to do the same in return. This act of nobility surprises even Rimmer himself.
In the episode Confidence and Paranoia, when Lister faints, Rimmer desperately tries to enlist the skutters and the Cat to move him to the medical bay as Rimmer is physically incapable. (It could, however, be argued that Rimmer does this because if Lister dies he will have no one left to talk to.)
In the episode Out of Time, Rimmer is revolted by his corrupted future self to the point he'd rather do battle with him than surrender. Then, when the others are killed, he frantically risks his life to bring them back.
In the episode Stoke Me a Clipper, Rimmer, after some persuasion, gives up his entire identity and everything that makes him Rimmer in order to continue the legacy of Ace, a man he despises.
In the final episode, Rimmer is in a mirror universe where he is captain, a dream of his come true. However, rather than stay, Rimmer returns to his universe in an attempt to rescue the others. In his case, this is also a noble act.
Rimmer's status as a hologram in most episodes of Red Dwarf is shown by the "H" on the center of his forehead. This feature is a common source of nicknames given to him by The Cat, such as "alphabet head" and "goalpost head". He also receives names for his flared nostrils, including the respectful form of address "flared-nostrilness" for the leader in "Rimmerworld". Unlike Lister and The Cat, Rimmer keeps his unmanageable hair relatively short, feeling that it makes him feel like a man. When Lister and The Cat respond to a drill too slowly, Rimmer argues for increased discipline and sensible haircuts, believing that "every major battle in history has been won by the side with the shortest haircuts".
Rimmer's Space Corps uniform changes several times, due to retconning (and a new costume designer on the show). In the first two seasons of the show it is a grey-and-beige shirt-and-tie ensemble; in seasons 3 and 4 this becomes a green suit with a shiny high-collared jacket, which changes to red in season 5; in seasons 6 and 7, Rimmer's jacket becomes quilted and is red when he is in soft-light form and blue when his hard-light drive is powered up; the new alive Rimmer in season 8 wears an all-beige uniform similar in design to the original. The hologram "H" on his forehead also changes from series to series: it starts as a dull grey colour and a blocky shape, then in season 3 it becomes bright blue and reflective, then in season 5 its shape is changed to a thinner and more stylised font. His "H" also briefly changes to a gold colour set inside a circle when he temporarily joins the holoship SS Enlightenment.
Among the actors who auditioned for Rimmer were Norman Lovett (who went on to play Holly instead), David Baddiel, Hugh Laurie, and Alfred Molina. Initially Molina was cast as Rimmer, however, the role was recast and filled by Chris Barrie, a professional voice-actor and impressionist. Barrie, who had originally auditioned for Lister, was familiar with Rob Grant and Doug Naylor having worked together on Son of Cliché and Spitting Image, and with the producers on Happy Families and various Jasper Carrott productions. He has appeared in all but four episodes of the show, which he missed in series VII due to scheduling conflicts.
Rimmer was played by Chris Eigeman in the first American pilot and then by Anthony Fuscle in the second pilot. The character's distinctive "H" was replaced with a marble-shaped object in the first pilot, but the "H" returned in the second one. Chris Barrie was given an offer to reprise his role, but turned it down for fear of being tied into a restrictive, long-term contract, which is common in American television production.
The female Rimmer in the Series II episode "Parallel Universe" was played by Suzanne Bertish, an actress primarily known for her classical stage work. She had been asked by director Ed Bye to play the part. "Young Rimmer", who had minor speaking roles in three episodes in Series III and IV, was played by child actor Simon Gaffney.