* AcceptableTargets: Adult gamers. Kovac buying himself a PlayStation to relax with (after he's been working twelve-hour shifts at one of the most stressful jobs imaginable, as the show is keen to remind us) is presented as a sign of his deteriorating mental health and that he's becoming a {{Jerkass}}. Bonus points for PacManFever noises as he plays.
** Note that this is in complete contrast with earlier seasons. Carter bonds with a leukemia patient over MortalKombat, Greene plays VideoGame/KillerInstinct at an arcade to take his mind off of the events of 'Love's Labour Lost'. The ER staff are all playing [[{{VideoGame/Doom}} Doom II]] when Doug is out saving a drowning boy.
** Psychiatric patients. There are many mentally ill patients who are written seriously, but plenty whose behavior is played for laughs, or portrayed as terrifying, nearly inhuman forces of nature.
* AlasPoorScrappy: The character of Lucy Knight was killed off because the producers and Kellie Martin both agreed that she wasn't working, basically being a CousinOliver. When they killed her off however, everybody was sad.
* AndYouThoughtItWouldFail: When this show premiered, it was going up against ''Series/ChicagoHope''. While not deriding {{ER}}, most critics deemed ''Hope'' the better show and predicted that it would win the ratings battle. Only for {{ER}} to trounce ''Hope'' so thoroughly that within weeks, ''Hope'' shifted its timeslot and was off the air within six seasons (perfectly respectable, but nowhere near ER's 15)
* CreatorsPet[=/=]DesignatedHero: Shortly after joining the show, Maura Tierney's character Abby Lockhart became its central figure, with many episodes focused on her and her miserable life--an unfaithful ex (and other dysfunctional relationships), mentally ill mother and brother, career troubles, alcoholism. Abby was always portrayed as the innocent victim in these situations, even though later dialogue revealed that she was just as responsible for the failure of her relationships as her vilified partners. The writers persisted in this despite viewers' fatigue with the constant focus on her.
* CrowningMomentOfAwesome: Many, but Doug risking his life to rescue a drowning boy in a torrential downpour, then furiously improvising all the way back to the ER, is probably the crowner. It also started the tradition of having one episode a season where one of the main characters must perform medical feats away from the ER, most of which are also [=CMoAs=]. The episode was also the highest rated in ER's history, pulling in 48 million viewers.
** Dr. Dave Malucci's final words when he is fired to Kerry Weaver, because Weaver was a very annoying character at that time to many fans and deserved to be told off.
* CrowningMusicOfAwesome: A trope-savvy Carter gleefully plays "Ride of the Valkyries" when he gets the chance to take out Benton's appendix. At the end of the surgery "Mack the Knife" can be heard.
** The main theme was composed by the composer actually spending a day wandering around a hospital and taking inspiration from all the various sounds he heard. If you listen you can pick out the beeping of machines, rattle of gurneys, and beating of a heart.
* DesignatedEvil: The man who shot the psycho who was rampaging around the city killing people with the intent of getting to Greene's family. Keep in mind said psycho had ''already shot this guy'' before he pulled a gun of his own and shot back. But just to assure us that guns are evil and anyone who would use one is a {{Jerkass}} at best, he's smug over his "kill" and [[MartyStu Carter]] lectures him on how it's pure luck he didn't shoot a baby or something.
** Conversely the cops complain that he didn't do a good enough job, noting that he shot the guy five times and he still survived, and claiming that if the police had caught up with him, he'd be in the morgue instead.
* [[DieForOurShip Die For Our]] [[StrawmanPolitical Political Views]]: One character ([[PuritySue young, idealistic, and full of promise]]) gets sent to Iraq and dies basically just to give a ''medical show set in Chicago'' a chance to criticize the war.
* DoubleStandard: The female staff ogling handsome male coworkers/patients/relatives of patients and commenting on their good looks is seen as perfectly normal and not the least bit unprofessional. Male staff ogling gorgeous female coworkers/patients/relatives of patients and commenting on their good looks are viewed as lecherous perverts. A very striking example of this is when Pratt is accused of groping a female patient (he didn't, but his efforts to put her at ease by telling jokes backfires on him). All the women not only instantly assume that he's guilty, they accuse ALL male doctors of having gone to medical school solely to have a chance to ogle women, while sanctimoniously--and falsely--insisting that they have never had an inappropriate thought about an attractive male patient.
** Also, it's totally acceptable for the medical doctors to bitch about unpleasant things that happen to them on their jobs, many of which are caused by sick or injured people who can't help puking or bleeding all over their caretakers, but any doctor from the psych department complaining about the behavior of their patients is treated to disgusted looks and snide remarks from the other staff.
** Corday accuses her mother of neglecting her or practically abandoning her in favour of her work, but her father gets a free pass. Her mother calls her out on this. Likewise, Carter confronts his mother for abandoning him and for not being there for him after his brother died, but the fact is that Carter's father was equally absent from Carter's life and his father gets absolutely none of Carter's angst.
* EnsembleDarkhorse: Greene and Benton (to the point that when they left, most of the audience left with them).
** Doug Ross, see Star Making Role.
** Corday has seen a surge of retroactive popularity due to a certain [[DoctorWho popular science fiction series]] that Alex Kingston has a role in.
** Hathaway was really popular with audiences, which is why she never succeeded in her suicide attempt.
** Jeanie Boulet was fairly popular, to the point that some critics called her re-appearance in Season 14 the best the show's been in years.
** While he could be a bit of a MartyStu later on in the series, Carter was also this due to his immense character development from NaiveNewcomer to TheHero over a period of 11 years on the show. It made [[BackForTheFinale his return in the final season]] all the more fitting.
* FanPreferredCouple: Still too many to list, but the most popular are Carter/Abby and Luka/Sam.
** Peter/Elizabeth is another popular one. Their relationship only ended because Eriq La Salle objected to his character [[WhereDaWhiteWomenAt dating a white woman.]]
*** American audiences were also baffled/disgusted by the relationship, instead trying to console themselves by believing that Alex Kingston was black. This in turn baffled Kingston, who claimed that inter-racial relationships are ubiquitous outside of the United States and was disappointed to find that in America attitudes weren't as liberal, and that Benton & Corday's relationship was so controversial.
** Mark/Susan, which never went anywhere solely because Sherry Stringfield left the show (losing millions in the process).
* FunnyAneurysmMoment: Abby's one episode storyline regarding breast cancer given that actress Maura Tierney was later diagnosed with the disease.
* HilariousInHindsight: A patient named Patrick (played by KevinMichaelRichardson) with an undisclosed mental condition (probably some form of autism) answers the phone at the ER when the Desk Clerk is away. He says '[[SpongeBobSquarePants ER? No, this is Patrick]]'
** Betsy Brandt plays a woman hooked on [[Series/BreakingBad crystal meth]].
** In the Japanese dub, AkioOhtsuka voiced Peter Benton. He already voiced [[Manga/BlackJack another doctor who works outside the medical establishment]]. Extra hilarity Benton is literally ''black'', compared with the other one.
** In one episode, a cop is asking Kerry Weaver for her and Peter Benton's name. The cop asks if it is spelt B-E-N-T-E-N, to which Weaver responds 'No, T-O-N'. Fast forward [[{{WesternAnimation/Ben10}} four years later...]]
* HoYay: Many instances, but most notably HeterosexualLifePartners Doug and Mark in the early seasons. Mark even says that he loves Doug...like a brother.
* JerkassWoobie: Dr. Romano, particularly once he loses his arm. Mark and Luka also qualify after hitting rock bottom in seasons four and eight respectively, though they were rather more of the "jerkass" side of the trope.
* LauncherOfAThousandShips: Neela. During the course of the show she gets to date Gallant ([[spoiler: who she married]]), Gates, Brenner, and Ray, not to mention her short-lived crush on Kovac as well as Dubenko's crush on her, and Pratt's flirtation with her that led to his break-up with Chen.
** A cross between this and genre launcher might be Abby. Once ER became the most popular show on television, it seemed like every new show from then on required at least one small, average-looking brunette with a rather caustic personality who is [[InformedAttractiveness considered the ideal woman]] by most of the male cast.
* LesYay: One of the female med students planted a kiss on Neela once. She was surprised, [[CrowningMomentOfFunny to say the least]].
** And before that, there was Maggie Doyle, Kim Legaspi, Kerry Weaver, Sandy Lopez...
* MartyStu: Carter. He's rich, handsome, kind, and a very talented doctor.
** Interestingly enough, when he ''isn't'' a MartyStu, he's usually a {{Buttmonkey}}.
*** This is due to CharacterDevelopment. When the series started, Carter was a naive newcomer who made many rookie mistakes and whose upbringing had made him nonchalant about peoples money-problem. As the show went on he lost his fumbling and his social ineptitude, but kept his money and his handsome-ness. His kindness was there from the start.
** He eventually became MartyStu, [[{{Anvilicious}} Dropper Of Anvils]] with the whole Doctors Without Borders thing not only making him seem even more heroic and selfless but giving him (and the show) opportunities to [[AuthorFilibuster lecture the viewers about social consciousness]].
* {{Narm}}: Dr. Romano's death, where an out of control helicopter falls on him just a year after another one cut off his arm. The writers seriously couldn't be a little more creative?
* NauseaFuel: Many, many of the patients' injuries. Carter gets queasy in the pilot seeing a man with a severe knife-wound.
* NightmareFuel: Innumerable. Has the [[NightmareFuel/{{ER}} nightmare sub-page]].
* RelationshipSue: Kem, who makes her significant other, Carter, look like the most flawed, well-rounded character ever created in comparison. A selfless manager of a Congolese AIDS clinic, which is already a pretty Sueish occupation, she's never allowed to be wrong about anything and often expresses what are almost certainly [[WriterOnBoard the writers' views]] on US foreign policy. She and Carter don't get along, which of course leads to [[TheMasochismTango wild hatesex]] and her getting pregnant, and suddenly Carter's willing to give up basically his entire life as he knows it for her sake. The kicker? [[spoiler:They break up. ''Offscreen'']].
* RetroactiveRecognition: Throughout the first few seasons of the show, many of its guest stars would go on to fame of their own--Lucy Liu, for example, spent several episodes playing the mother of an AIDS-stricken infant, Bradley Whitford played the grieving husband of a woman who died in childbirth. Kirsten Dunst played a runaway, etc.
* TheScrappy: Carla Reese was a bitch from the time she got pregnant right up until she died, and even a little bit afterwards as well (with confirmation that Reese isn't Peter's son). Apparently her actress was a real life one for the producers, who opted to fire her for her unpleasant behaviour.
* SeasonalRot: The show had a tendency to get preachy in later seasons. Many consider the show to have effectively ended after Season 8 with Greene's death and Benton's departure, some don't make it past the departures of Ross and Hathaway.
** This claim isn't as subjective as one might think. During the first eight seasons ER was consistently in the top 4 in Nielsen ratings (the lowest rated was Season 6 at #4). However, with season 9 it fell to 6th Most watched and kept falling. The show's problem is it went on too long and ultimately no one was watching. Not even the promise of bringing back all the old stars (including George Clooney) was enough to put ER back at the top (although the final season was much better rated than the fourteenth season, which was by far the lowest rated).
** Early season 6 was a mess, with new characters being introduced (Kovac, Finch, Malucci, Chen and eventually Lockhart) or old characters leaving (Boulet, Knight and eventually Hathaway) the show every other episode. A fair amount of these new characters were fairly weak and/or uninteresting with Kovac being the notable exception. However, the season was redeemed in the end by giving us [[spoiler:the first death of a main cast member, Lucy, and a happy ending for Carol and Doug]]. Unfortunately, from then on whenever the show tried to WinBackTheCrowd, it would always fall to trying either one of these two things (either kill someone or give them a happy ending) with returns diminishing practically each time they tried it.
** Because it was Carter's last season, season 11 tried to be all about him and gave a storyline that deliberately went into TearJerker or heartwarming territory. It didn't go well, and while most people credit season 13 as the season the show went back on track, season 12 was already a big improvement over 11.
** Season 5 is considered by many to be the first genuinely weak one in the show's history--the entrance of Lucy Knight was handled very badly, as was the exit of Doug Ross, and numerous other storylines, such as a deranged woman being hired as the department's new chief, were downright embarrassing. The shakiness of early Season 6 is no doubt due to attempts at rectifying this. Despite this, Season 5 was #1 in the ratings (although its quality was probably partly the reason for Season 6's placement at #4).
* SequelHook: A fair amount of episodes in Season 8, as well as the descriptions for the DVD box-set read like a sales pitch for the Anthony Edwards/Mark Greene-less Season 9. Particularly egregious is the season finale, which completely undercut the powerful and sad ''On The Beach'' for a completely obvious sequel hook that could have easily been the Season 9 premiere instead.
* TearJerker: dozens; most notably, "Love's Labors Lost." "On The Beach" as well, especially for many fans.
* WhatTheHellHero: Benton's final story arc before his departure from the show comes off as this, as in the wake of [[spoiler: Carla's death]] he suddenly decides that Roger, who loved and took care of Reese like his own son, doesn't need to be in the boy's life any more and enters into a fierce custody battle with him. [[spoiler: Benton wins, but the viewer arguably feels so sorry for the now doubly-bereaved Roger that it's something of a hollow victory.]]
* TheWoobie: Just about anyone in the main cast qualifies for this. Having to deal with the stress of working long shifts in the hospital has quite an effect on their lives. Just a few of the personal problems that pop up in the series:
** Mark Greene: First wife cheats on him and leaves him for the other man, Susan leaves him before they can even have a relationship, he grossly mishandles a routine delivery (compounded by a complete lack of help from anyone in obstetrics), resulting in the mother's death, gets the crap beaten out of him by an unknown assailant. Has a distant relationship with his tough military father. Loses his mother to dementia and eventually loses his father to lung cancer. Suffers a brain tumour. Oldest daughter becomes a rebellious brat, leading to infant daughter nearly dying of a drug overdose, before he finally [[spoiler:dies from a recurrence of his brain tumour, leaving both daughters without a father during their formative years]].
** Doug Ross: Was abused and eventually abandoned by his father, emotionally damaging him so much that for years, he's unable to maintain a healthy relationship with a woman, costing him the woman he loves (for a time). Suffers through Carol's suicide attempt and her rejection of him afterwards. Hits rock-bottom after one of his one-night stands ''dies'', nearly costing him everyone's personal and professional respect. Father dies without him ever getting a chance to reconcile with him or tell him off. Then after ''finally'' getting his life together--reconciles, proposes to,and moves in with Carol, receives a promotion at work--he blows it by being involved in the MercyKill of one of his patients, forcing him to resign and leave town in disgrace, then spends a year and half away from his beloved Carol, missing out on the birth of his children and the first few months of their lives.
** John Carter: Constantly trod on by Benton as a student and resident, loses a friend to suicide and grapples with guilt over not being there for him, and has numerous relationships fail. Gets literally stabbed in the back by a deranged patient and [[spoiler:is forced to watch Lucy bleed out next to him]]. The fallout of the attack eventually leads him to become addicted to painkillers, for which the ER staff force him to check into rehab. His mentor leaves the hospital to join private practice. His own child ends up being a stillbirth and even as the series ends, his relationship with the child's mother is left ambiguous. He suffers from chronic kidney problems as a result of the stabbing, leading him to require a transplant.
** Carol Hathaway: Tries to commit suicide after being jerked around by Doug. Tries to adopt an AIDS-stricken little girl (who had no one to take care of her) only to have her efforts blocked because of said suicide attempt. Gets left at the altar when her fiancÚ correctly deduces that she doesn't really love him and is still in love with Doug. Has to dump another boyfriend when he refuses to admit that he even has PTSD (regarding the death of his friend) much less get help for it. Suffers a HeroicBSOD when Doug reveals that he has to leave her in season 5.
** Peter Benton: Despite being a skilled physician, is in complete denial about how ill and frail his mother is becoming. Cannot break away from the hospital to spend time with his mother (even missing her birthday to save a Neo-Nazi from a stab wound to the chest). Feels responsible for her injuries when he falls asleep while looking after her and she promptly falls and breaks her hip. Suffers a HeroicBSOD when she dies a few months later. Falls in love with her Physician Assistant but she rejects him twice, first when he's bereaved over the loss of his mother, second in favour of her (adulterous) husband, finds out a few weeks later that she left her husband, then goes through an HIV scare when she reveals that she's HIV-positive. Is shunned by fellow staff members when he blabs about co-workers mistakes. Is guilt-ridden over an underling's suicide (he hounded him mercilessly). Son is born prematurely, then ends up suffering a hearing impairment. Becomes temporarily blacklisted from practising after angering Romano. Learns that son isn't biologically his and nearly loses him in a custody battle.
** Susan Lewis: Her boyfriend suffers a breakdown and mysteriously disappears without a trace, only for it to be revealed months later that he's run off with another woman. She's constantly hounded by {{Jerkass}} senior physicians (to his credit, one of them apologizes after she saves his life). It's implied she's spent her entire life picking up after her perpetually screwing up older sister, including caring for her baby after she abandons the child. Comes to care for her niece as if she were her own daughter, only to lose custody of her when her newly-reformed sister reappears. Sees a therapist to deal with said loss. Develops feelings for her best friend, but then has to leave him before they can have a relationship. When she comes back, he's married with a child. She then has to grapple with the thought of him dying. Loses out on a tenured position because, unlike the affluent Carter, she cannot secure sufficient grant funding.
** Jeanie Boulet: Contracts HIV from her unfaithful husband (and ends up seeing him die, as she reveals that he passed away with a weight of 78 pounds) and promptly spends years fearful of embarking on a relationship because of this. Reunites with her adulterous husband only to be separated from him once again when he can only find work in Atlanta. Becomes friends with Anspaugh's twelve year old son, only to see him finally succumb to his constantly recurring cancer.
** Kerry Weaver: Mother gave her up for adoption, leading her to wonder for many years if it was because of her birth defect. Suffers a massive inferiority complex which seems to manifest itself in her need to overachieve at work and to back stab almost everyone. Is disliked by most of her colleagues. Undergoes a crisis in discovering her sexuality, and witnesses her girlfriend Sandy die from injuries sustained in a fire, then battles her homophobic family for custody of their son. Finally meets her birth mother only to find that she is a Conservative Christian fundamentalist and cannot love her or accept her because of her belief that homosexuality is wrong.
** Elizabeth Corday: Begins a relationship with a work colleague that ends when he more-or-less refuses to support her. Has her fellowship terminated by Romano because she wouldn't go out with him. Has to re-do her internship to stay in America, leading to her being over-worked and exhausted and, as a result, almost lethally injecting a patient with a fatal dose of magnesium. Sees her husband [[spoiler:succumb to his brain tumor]] and realizes just how alone Romano was when she ends up being the only one to show up to his funeral.
** Robert "Rocket" Romano: Despite being the epitome of Jerkass, still gains sympathy from having his arm chopped off by a helicopter. Followed by his eventual [[DroppedABridgeOnHim death by helicopter]].
** Luka Kovac: Feels survivor's guilt following the death of his wife and children, in part because he feels responsible for their deaths (not leaving Croatia early enough and staying to administer CPR to his dying daughter when his wife was bleeding out). Started to recover when he fell in love with Carol Hathaway, only to be setback when she broke his heart by leaving town to be reunited with Doug. Then he suffered a HeroicBSOD after killing a man who was attacking him and Abby, leading them to have a thoroughly dysfunctional relationship, then battled depression that culminated in him nearly killing a co-worker in a car accident. Not until he went to Africa did he get his act together, and even then, he almost died over there.
** Abby Lockheart: Suffered a rough childhood, due in large part to her mother suffering from bipolar disorder (as did her brother, who she frequently had to look after). Ended up with a drinking problem that plagued her all throughout the show,frequently jeopardizing her career and relationships. Got shot whilst carrying her and Luka's child, putting both mother and son in jeopardy.
** Jing-Mei Chen: Suffers a HeroicBSOD after almost killing a patient as a medical student, forcing her to realize that she doesn't have what it takes to be a doctor. Has to endure pregnancy, childbirth, and giving her baby up for adoption alone because she has no real relationship with the baby's father, and because of her disapproving family--the child is part African-American. Is turned down for the coveted position of Chief Resident, then after appealing and getting the job, bungles it within weeks with a misdiagnosis that leads to a patient's death. This leads to a harsh rebuke from Weaver, as well as Weaver backstabbing her to ensure that she takes all the blame for the incident. Becomes so stressed by her the status of her ailing father that she lets him convince her to fatally inject him with Potassium.
** Greg Pratt: Continuously passed over for promotion to Chief of Emergency Medicine.After FINALLY being given the position, he ends up dying after suffering injuries from an ambulance explosion. Because of RuleOfDrama, Pratt died the very same day he was going to propose to his girlfriend and before his superiors had a chance to inform him he'd gotten the job as chief of the ER.
** Neela Rasgotra: Neela perhaps suffered the most angst of anyone in the last few years, but enduring the death of her husband in the Season 12 finale is probably the standout moment.
** Sam Taggart: Frequently butts heads with her ex-husband, leading to his kidnapping and raping her. Also has to constantly deal with the troubles of raising her son as a single parent.
** Ray Barett: Frequently the UnrequitedLover for Neela. Ends up getting run over by a truck and loses his legs in the season 13 finale.
** Archie Morris: Is (initially) an incompetent screwup who no one likes or respects. After getting his act together, gets kidnapped by a teenager in season 14 (so that Archie could operate on his girlfriend). Comes to bond with the kid during the course of their time together, only to see the young man get killed by a sniper bullet. Witnesses his best friend Greg Pratt die after suffering injuries from an ambulance explosion.
** Tony Gates: Raised by an alcoholic father, gets badly injured by an explosion and Nina has to operate on him out in the field, is manipulated by a woman to sleep with her because she'd paid for his tuition, said woman commits suicide when he decides to leave her for Neela, not before informing him her kid was his, but after getting his hopes up a paternity test reveals she isn't and he loses a custody battle with her grandparents.
** Catherie Banfield: Revealed to have lost her young son to acute leukemia, something that she didn't recognize until pointed out by Dr. Greene, leaving her immensely guilty. Goes through attempts to have another baby in season 15, with difficulty.
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