* AcceptableTargets: Adult gamers. Kovac buying himself an [=XBox=] 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.
** 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.
* 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=].
* 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.
* 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.
* [[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.
* FanPreferredCouple: Still too many to list, but the most popular are Carter/Abby and Luka/Sam.
* FunnyAneurysmMoment: Abby's one episode storyline regarding breast cancer given that actress Maura Tierney was later diagnosed with the disease.
* HoYay: Many instances, but most notably HeterosexualLifePartners Doug and Mark in the early seasons.
* 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 GenreLauncher 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]].
* 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'']].
* 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. However, with season 9 it fell to 6th Most watched and kept falling. The show's problem is it went on too long.
** Early season 6 was a mess, with new characters being introduced or old characters leaving the show every other episode. 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]].
** 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.
* TearJerker: dozens; most notably, "Love's Labors Lost." 'On The Beach' as well, especially for many fans.
* TheWoobie: [[spoiler: Greene barely gets to spend any time with his new wife and daughters (one of which was still only a baby) before he dies from an inoperable brain tumour. His baby daughter didn't even get to know her father]]
** Made even worse by the fact that he was in the middle of some serious family drama right when he was being diagnosed.
** 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, resulting in the mother's death, gets the crap beaten out of him by an unknown assailant, oldest daughter becomes a rebellious brat, leading to infant daughter nearly dying of a drug overdose, before he finally [[spoiler:Dies from a brain tumor]].
*** 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 stabbed in the back and [[spoiler:is forced to watch Lucy bleed out next to him]]. His own child ends up being a stillbirth.
*** Carol Hathaway: Tries to commit suicide after being jerked around by Doug. Tries to adopt a little girl only to have her efforts blocked because of said suicide attempt. Gets left at the altar when her fiance 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. 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. Begins a relationship with her caretaker which ends when she refuses to leave her husband for him, then goes through an HIV scare when she reveals that she's HIV-positive. Is shunned by fellow staff members when he blabs about coworkers 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 practicing after angering Romano.
*** Susan Lewis: Her boyfriend 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, only to lose custody of her when her newly-reformed sister reappears.
*** 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.
*** Kerry Weaver: 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.
*** Elizabeth Corday: 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 Kovic: 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 coworker 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.
*** 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.
*** 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.
*** 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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