There are plenty of things that RealLife people rarely see as funny, even when they're PlayedForLaughs.

* {{Death|AsComedy}}: Whether it be natural causes, unfortunate accidents, or intentional homicide and murder, it is almost always completely unacceptable to [[NeverSpeakIllOfTheDead talk positively about a real-life person's death]]. The sole exception to the rule [[SpeakIllOfTheDead is if the person was a despised criminal, bigoted extremist, dictator, terrorist, exceptionally mean-minded boss, or sympathizer for any of the former five categories]].
** Another possible exception is when the cause of death is unusually bizarre or the deceased was TooDumbToLive and got killed by doing something ''really'' stupid. (The Website/DarwinAwards thrives on this.)
** The Sick and Dying: Similarly, speaking ill of those at Death's door is considered extremely bad form if not taboo. And ''never'' make light of the illness, injury, etc. that caused the situation.
** {{Suicide|AsComedy}}: Although {{UsefulNotes/suicide}} is occasionally used for [[BlackComedy dark humor]] in some media, this can tread into ''very'' dangerous territory because it may {{UsefulNotes/trigger}} people who suffer suicidal thoughts. Even if one doesn't suffer suicidal thoughts, it may scare them or make them sad, especially if they knew someone who committed suicide. Moreover, [[SuicideDare telling someone to go kill themselves]], even as a [[JustJokingJustification "joke"]], is considered to be [[MoralEventHorizon completely beyond the pale]]; not least because depressed or mentally ill people [[RhetoricalRequestBlunder may decide to]] [[GoneHorriblyRight take you up on it]].
* [[BlackComedyRape Rape]]: It's considered to be one of [[RapeIsASpecialKindOfEvil the most serious crimes]], because of the devaluing of the personhood of the victim and the mental trauma that surviving victims have to suffer for the rest of their lives. And although PrisonRape is often treated as a source of dark humor due to sex offenders and other convicted criminals often being viewed as [[KarmicRape acceptable targets]], the vast majority of real-life prison rape victims [[https://www.hrw.org/reports/2001/prison/report4.html are young, white, small, effeminate, passive in nature, and/or part of the LGBT community]] — especially poor qualities for public policy and social norms to bring such a cruel punishment on. This isn't even mentioning that most imprisonments are for non-violent drug offenses.
* The Male on Female version of DomesticAbuse.
** Sitcoms' use of DoubleStandardAbuseFemaleOnMale variety has been gradually starting to get this reaction, although so far it hasn't been nearly vocal enough to convince the networks to stop using it.
** AbusiveParents, particularly as it was used in professional wrestling where -- to mock a baby{{face}} opponent -- the {{heel}} claims that a beaten child wants to go live with said babyface "because he don't beat nobody!"
** {{Hilariously Abusive Childhood}}s can fall victim to this if the abuse fails to [[CrossesTheLineTwice cross the line twice]] and ends up being uncomfortably realistic to viewers.
* Kidnapping -- It's sometimes played for comedy if the kidnapper is very incompetent, but usually it's too serious to be comedic, especially if the one being kidnapped is a pregnant woman, an animal, or an actual kid and clearly shown to be terrified. And even more so if it also leads to an even more serious crime, like the aforementioned rape or murder.
* Any felony where the [[WouldHitAGirl victim is a woman]] or ''especially'' [[WouldHurtAChild a child]]. Furthermore, saying anything negative about the victim or positive about the criminal is considered equally deplorable, as is supporting people who sympathize with the criminal.
* MaximumFunChamber: ColdBloodedTorture, played for humor. Because who can't see the lighter side of agonizing pain?
* [[ButtMonkey Butt-Monkeys]], [[DesignatedMonkey if taken too far.]]
* NoSympathy
** NoSympathyForGrudgeholders
** Some of the more severe cases of KafkaKomedy (too much Kafka, not enough comedy)
* HarsherInHindsight moments.
* [[TheMentallyDisturbed Insanity and Mental Illness]], particularly as a result of intentionally inflicted mental distress such as {{Gaslighting}}. While insanity can be played for laughs sometimes, it's becoming less acceptable, and it's even more unacceptable to play a specific mental illness for laughs.
** Also [[TheAlcoholic alcoholism]]. While people often make jokes about characters being drunk (provided they're not driving, see below) or [[INeedAFreakingDrink wanting to drink]], implying that they actually have a problem is right out unless it's [[DrunkOnMilk a parody using a non-alcoholic substance acting like alcohol]].
* Mocking or criticizing: Targets are treated as too sacred and sensitive of a topic.
* UnprovokedPervertPayback: Expect this to happen at least once in a [[HaremGenre Harem]] anime.
* AprilFoolsDay jokes if they seem to come across as way [[PrankGoneTooFar too cruel or unfunny]].
* [[BlackComedyAnimalCruelty Jokes about animal cruelty]]
* {{Cruel Twist Ending}}s
** DiabolusExMachina
** {{Karmic Twist Ending}}s if the audience believes that what caused "karma" to punish the character is too disproportionate.
* KarmicMisfire: When the Karmic Butt-Monkey gets framed by the true [[KarmaHoudini guilty party]] and get [[spoiler:(unfairly)]] punished.
* Social problems
** [[TheBully Bullying]]
** [[AllOfTheOtherReindeer Exclusion]]
** [[LonersAreFreaks Loneliness]]
** TherapyIsForTheWeak, especially offensive to people who go to therapy, went to therapy in the past, or know someone who is or was in therapy.
* [[LoveHurts Heartbreaks]], especially since they can take a serious toll on your mental and even physical health.
* Paraphilias
** [[BestialityIsDepraved Bestiality]]
** [[PaedoHunt Pedophillia]]
* [[PoliticallyIncorrectVillain Racism and other bigotry]]
** [[{{Reichstropen}} Anything having to do with the Nazis]] -- even if it portrays them in a bad light (there are some exceptions, but not many)
*** AdolfHitlarious (treating Hitler as a buffoon when he was really a genocidal maniac)
*** ThoseWackyNazis, if UsefulNotes/TheHolocaust is downplayed or treated too flippantly.
** [[ModernMinstrelsy Racial stereotypes played for mockery]]
*** {{Blackface}}
*** {{Yellowface}}
*** HollywoodNatives
** [[NWordPrivileges Using the N-word]], especially if the characters saying it are white, and regardless of context, however even in productions involving black characters, use of the word for comedic reasons is dicey depending on the venue.
* [[HeteronormativeCrusader Homophobia and Transphobia]]
* [[HeManWomanHater Misogyny]]
* [[DownerEnding Downer Endings]]
* DrunkDriver. It used to be a source of humor, but the usual reaction now is "My God, s/he's going to kill somebody!"
** SorryOciffer: Ha ha, somebody behind the wheel is too drunk to speak straight.
* {{Trauma Conga Line}}s
* BlamingTheVictim
* TheWoobie (and similar tropes, such as DesignatedMonkey): Making fun of someone's misery (especially if it's realistic and/or overwhelming) can backfire ''hard''.
* Unemployment and / or Poverty, particularly during times when economies the world over are in a downturn. This can come off as KillThePoor levels of insensitivity.
* {{Slavery|IsASpecialKindOfEvil}}.
* Fake pregnancy jokes can come off as this when the person playing the prank makes it less obvious that they're joking.
* Uses of ApocalypseHow can come off as this when PlayedForLaughs, as the end of the world is often a serious matter in lots of fictional material and can cause NightmareFuel for the easily-frightened.