These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Adaptation Displacement: Most are aware that it's based on the 1970 film, but how many fans know of Richard Hooker's MASH: A Novel About Three Army Doctors (1968) that inspired the film?
It might just be fandom overthinking things but the LiveJournal consensus on Hawkeye is that he's bisexual and manic-depressive. To be fair, the LiveJournal consensus on everyone is that they're bisexual and manic-depressive.
There is also debate about how sympathetic or unsympathetic we are supposed to feel towards Frank. Is he just a stupid Jerkass? Or a Jerkass Woobie who, nevertheless, did not deserve to be bullied and tortured the way he was? A doctor who was cracking under pressure (Henry Blake described him as "a fair but competent" doctor in season one, suggesting that Frank wasn't necessarily a bad surgeon but merely an inferior one when compared to Hawkeye and Trapper, and later BJ)? Or, a demented, deeply disturbed sociopathic Man Child who was actually dangerous (recall the time he tried to get Hawkeye hanged.)? Perhaps all of the above?
Pre-Flandarization, some episodes actually seem to portray Frank as the Only Sane Man (albiet a Jerk Ass version of one) in the 4077, given that he is the only one who acts like they are all in a war zone 3 miles from the front lines. Everyone else seems to think they are on vacation between OR sessions. If you watch the first 5 seasons with your focus on Frank, the show tells the tale of a man who is pushed over the Despair Event Horizon by his asshole roommates and eventually snaps when the woman he loves runs off with another man.
Ass Pull: "The Nurses", in which a nurse's husband is on leave for 24 hours so Hawkeye and BJ make up a fake diagnosis to keep him quarentined in Margret's tent so the nurse can be with him... despite the VIP tent being vacant.
Awesome Music: A special, more military version of the "Suicide Is Painless" theme was used for parts of "Bug Out", parts One and Two (Which, incidentally, was the series' first Cliff Hanger episodes), including one point where the climax is hit during a shot of Potter and Houlihan on top of Sophie, Potter's horse. The music was never used for any other episode.
Badass Decay: Few fans remember that crazy CIA agent Col. Flagg was a seriously dangerous character in his first appearance, even pulling a pistol on Hawkeye. He was also far more laid back and even participated in the camp poker game.
Better on DVD: The general consensus. While there isn't much continuity to screw up, some stations tend to cut up episodes for time, or not air certain episodes for some reason or another. The DVD also gives the viewer the option of watching it without the Canned Laughter.
Black Hole Sue: Once Alan Alda got creative control. Hawkeye became the center of the universe, the linchpin of reason and sense (well, even before Alda took over Hawkeye had some of this). While still fallible and capable of making mistakes, his opinions were nevertheless the moral compass others were meant to set their course by, and everyone from Father Mulcahey to Colonel Potter came to him for advice regularly. Probably the most blatant this got was the aptly-named "Hawkeye", which is pretty much literally nothing but a thirty minute long stream of consciousness monologue by Alda. It should be noted that "Hawkeye" was written and filmed before Alda took creative control of the show.
Broken Base: The series seems firmly divided between fans who preferred the earlier seasons (which focused more on comedy) and the later seasons (that focused more on drama).
Crack Pairing: Ho Yay factor of Hawkeye and Trapper (and later B.J.) aside, a number of fans like to pair Charles with Klinger (and even more ironic, this precedes David Ogden Stiers's outing).
Hawkeye can come off this sometimes. Every good character seems to love or adore him, and while sometimes justified for The Ace characters, it may be overbearing.
Both creator Larry Gelbart, and series writer Ken Levine, have said that of all the characters on the show, Radar was their favorite to write for. It sometimes shows as nobody could think wrong of cute little Radar.
Lt. Col. Sam Flagg was one of the show's most memorable recurring characters despite by only appearing in seven episodes. Word of God (specifically Ken Levine) said that they really enjoyed writing Flagg but kept appearances to a minimum to avoid wearing out his welcome and turning him into The Scrappy. Possibly eight, if you consider that Edward Winter played Captain Holloran, an intelligence officer, before playing Flagg. He plays poker with Sidney, which Flagg refers to, leading many to believe Holloran was an alias of Flagg's.
Maj. Sidney Friedman, everybody's favourite shrink, was popular with viewers.
Fair for Its Day: The episode "George" comes off today as extremely dated, handling the subject of homosexuality in the military poorly and misleadingly. However, in the 1970's, having an episode that portrayed a gay soldier as a sympathetic character and a courageous Marine was really quite amazing. Although technically, it should be dated, as it takes place in the '50s with '50s sensitivities.
Same can be said for the episode, "Inga": it was written and directed by Alan Alda, who was very much an outspoken advocate for Women's Rights, and at the time this episode aired, was during the height of Feminism. Today, however, the episode comes off as very clumsy, dated, and downright sexist, particular how Hawkeye and later Charles have their male egos bruised by Inga showing them up (though it was never her intention to do so: she was there, as a doctor, simply to help keep the 4077th up to date with the latest surgical techniques).
In a very early episode, Margaret (who has an absolutely gorgeous curvy body, by the way) is feeling self-conscious about her weight and laughs about "throwing up" later to lose it. Bulimia was not a well-known disease in the early '70s, let alone the early '50s.
The episode that guest stars Patrick Swayze as a patient diagnosed with terminal cancer.
In-universe example: in one of the early seasons, Hawkeye pretends to be having a psychological breakdown in order to get leave in Tokyo. Cue the series finale.
In "O.R.", Hawkeye tells Henry that he'll die an old man in his bed in Bloomington, Illinois. Ouch, show.
In a first-season episode "Dear Dad, Again", Hawkeye says that he's surprised Father Mulcahey doesn't "go deaf from the sound of all the commandments breaking around him". In the series finale, Father Mulcahey's hearing is severely damaged (perhaps permanently) by a nearby mortar round.
In season 1's "Henry Please Come Home", Blake tells Hawkeye, "One of these days Frank's gonna throw the book at you, and I won't be around to help." Sure enough, in "The Novocaine Mutiny", Frank has Hawkeye court-martialed for alleged mutiny.
Growing the Beard: Though opinions may vary, the series became a good deal more thoughtful, sincere, and mature with the departure of Trapper and Colonel Blake and the arrival of BJ and Colonel Potter. Of course, some would say the beard became overgrown and the series verged on Wangst the more control Alan Alda gained over it. "Growing The Moustache," perhaps? The rule with some fans is to skip any episode where BJ has a moustache - those last seasons are the ones with the highest quotient of Wangst, Anviliciousness, and Cerebus Syndrome.
"Boy, what I wouldn't give to wake up one morning, look down, and find myself gone." ~Henry Blake
Hearing the doctors complain and think they should just leave Korea to sort itself out becomes a lot harsher when you know what happened to North Korea.
When Margaret first gets engaged to Donald, Frank (in an obvious attempt to get into her pants) theorizes that Donald is no good. She (humorously and good-naturedly) turns him down. Several seasons later, we learn that Donald has been stealing Margaret's paychecks for himself and sleeping around behind her back while she has been faithful to him. This revelation leads to them divorcing.
On that point, when Hawkeye and B.J. replace Margaret's engagement ring, the seller messes up the inscription to read," Over hill, over dale, our love will ever fail."
Charles once comments that "there is very little shrapnel flying around Boston," a comment that becomes painful in the wake of the 2013 Boston Marathon Bombing.
Hawkeye's attempts at getting out of the 4077 by pretending to have gone nuts leave a bitter taste in the mouth after the Finale.
Likewise, Frank and Margaret playing up his symptoms when they realize this is their chance of getting rid of him.
In one very early Season One episode, Henry dismisses another one of Frank's complaints against Hawkeye, wanting him charged with insubordination, but then Henry says to Hawkeye, "You know, Pierce, one of these days, Frank's gonna throw the book at you, and I won't be around to help." Sure enough, later in Season Four, after Henry's death, Frank successfully takes Hawkeye to court on mutiny charges (of course, Potter was able to help, as were B.J. and Radar, but still).
Hawkeye and B.J. also had their moments. From the final episode:
Hawkeye: Look, I know how tough it is for you to say goodbye, so I'll say it. Maybe you're right. Maybe we will see each other again. But just in case we don't, I want you to know how much you've meant to me. I'll never be able to shake you. Whenever I see a pair of big feet or a cheesy mustache, I'll think of you.
B.J.: Whenever I smell month-old socks, I'll think of you.
Hawkeye: Or the next time somebody nails my shoe to the floor...
B.J.: Or when somebody gives me a martini that tastes like lighter fluid.
Hawkeye: I'll miss you.
B.J.: I'll miss you, a lot. I can't imagine what this place would've been like if I hadn't found you here.
"What if I were dying? Would you hold me and let me die in your arms, or leave me on the floor to bleed?"
Hawkeye also seems to enjoy having fantasies that involve B.J. in romantic situations.
When Blake is saying his goodbyes in "Abyssinia, Henry", he holds out his hand for Hawkeye, who says, "I'm afraid just a handshake won't do it, Henry," and promptly smooches him on both cheeks.
This website has a list of every single slashy quote from the entire series. It's... extensive.
He becomes much more sympathetic if you pay attention to the snatches of his backstory that he occasionally reveals (usually while drunk). If you had his home life, you'd probably be pretty messed up, too.
Magnificent Bastard: Charles manages to set up Hawkeye and BJ against Margaret in an escalating prank war that he's orchestrating. He also is the one who foils Col. Flagg's effort to have Hawkeye charged as a Communist subversive, and sets up visiting (and incredibly annoying) surgeon Dupree to ride Col Potter's horse and gets him in serious trouble as a result.
Charles demonstrates this in his first episode, turning Hawkeye's prank around on him and even being a Gentleman Snarker about it.
Frank was always a Jerk Ass, but having Hawkeye court-martialed on spurious charges knowing perfectly well that Hawkeye would be executed if he was found guilty...?
Frank when he stole a general's gun and let Radar take the rap for it, facing a possible court martial. The only reason he even returned it was because Major Houllohan confronted him about it.
Narm: Any time Trapper would dramatically declare his longing to be home with his wife and the horrors of being separated from his family by the war, since chances were almost 100% that the episode would also show him thoroughly enjoying her absence with whatever hot girl crossed his path. Possibly the same with Colonel Blake, though since he was often less brazen and smug about his conquests, it didn't cause quite so much dissonance.
The episode "Dreams" had a very Twilight Zone-y feel to it. As it includes dream scenes like Margaret in a bloody wedding dress and Hawkeye losing his arms and screaming to the sound of helicopters.
The ghosts in "Follies of the Living - Concerns of the Dead".
The scenes in "Point Of View" where Private Rich is choking and struggling to breathe due to his throat injury. Since the episode is shot from his point of view, we don't actually see what the injury looks like, but the sounds alone are terrifying.
Older Than They Think: Alan Alda's Hawkeye talks and acts a lot like Groucho Marx. Then again, Groucho Marx was still quite popular in the '50s.
Recycled Script: Plenty, but of note is the seventh season episode "Preventative Medicine" had a plot that was essentially the same as that of the first season episode "The Ringbanger". In keeping with the show's gradual slide into drama, however, the psychological gaslighting of the original was changed to coercing the victim into unnecessary surgery, to which B.J. took a moral objection.
The "sidelining an officer via unnecessary surgery" angle had itself been used before, in a secondary plot involving Col. Flagg in season 3's "White Gold".
Interestingly enough, the original script for "Preventative Medicine" had B.J. going along with Hawkeye's scheme (just as Trapper had in the earlier episode), but actor Mike Farrell objected as he believed that B.J. would never do such a thing. The producers eventually agreed, so they let Farrell and Alda ad-lib their way through the scene, acting and reacting the way they felt their characters would.
Two conversations between a Swampman and his nominal nemesis (Trapper and Frank in "O.R.", Hawkeye and Charles in "Sons and Bowlers") were recycled pretty closely in subject matter. Being the different characters they were and the different points in the show, though, the scene with Frank saying he came from a loveless home was Played for Laughs, while Charles' admission of a distant family life and envy of Hawkeye was treated as showing his good side.
In "Pay Day" in season three, Hawkeye complains to Radar about how he could have made $3,000 in his civilian practice, and Radar pulls a few strings and has him paid. "Back Pay", in season seven, has Hawkeye outraged that doctors in the states make $4 an x-ray for draft boards, so he bills the Army for his services. Both have him get into trouble with a bureacratic officer and has to repay the money he obtained.
Some younger viewers may wonder what the big deal is, but you can thank M*A*S*H for pretty much every Dramedy series that's come in its wake.
Before M*A*S*H, if an actor left a show and a Suspiciously Similar Substitute came in, it wasn't the norm for the change to become an in-universe plot point. In an era when there were no DVD box sets but there were reruns, TV episodes were created so that they could be watched in any order and old characters were never mentioned again after their actors left. Because, you know, that might shock and confuse people. M*A*S*H is an early (and, by today's standards, primitive) example of long-running continuity in a television show.
Special Effect Failure: "The Trial of Henry Blake" has a scene of Klinger attempting to escape the camp via hang-glider. This is shown with very obvious green-screen usage.
When Klinger and Hawkeye go around camp nude in different episodes (Klinger to convince a General that he's insane, Hawkeye to win a bet with Trapper), the underwear the actors are wearing is plainly visible.
The show's interior soundstage set includes some "outdoor" portions immediately surrounding the Swamp, O.R., and Mess Tent (complete with painted mountains, plastic trees, etc.) which were used for some episodes when the actual outdoor set at the Malibu Ranch was unavailable. In certain episodes they'll cut between the interior and exterior sets in the very same scene!
In the episode where Radar rescues Sophie (at the time a stallion instead of a mare), BJ and Hawkeye are trying to extract a piece of shrapnel from the horse's rump, leading it to kick through the wall of the supply building. The legs are obviously wooden models, and one of them breaks and is hanging from splinters after the second kick.
The writers have said they eventually had to phase him out of the show, because he was too silly and one-dimensional, and thus would have been out of place with the direction the show took in tone. He does, however, make an appearance in a two-parter episode of the After Show.
Values Dissonance: The episode where Hawkeye, BJ and Col. Potter arrive at camp driving drunk in celebration of making a General look ridiculous may have been a standard comedy business in the late 1970s, but now a typical viewer, well aware of the dangers of drinking and driving would be alarmed that they could have killed someone, or themselves.
There's also the fact that Trapper is considered to be a positively-viewed character, despite his nickname coming from the fact that he raped a girl.
Only in the novel. And even there, it's kind of implied that it was a reputation-saving False Rape Accusation on the part of the young woman in question.
"House Arrest" features a shockingly cavalier attitude toward rape, which Larry Gelbart has said is one of his biggest regrets about the show.
Word of Dante: You have to come to expect some of this for such a Long Runner, and a really popular one at that. The biggest example is probably the infamous "lost episode" entitled, "A Sound, a Song, and a Surprise", which supposedly contains a version of the theme song with lyrics sung during the opening titles, and a plot basically filling in all the gaps that were left open during the rest of the series (including off-screen departures of Spearchucker and Trapper, among other things). Further examination and investigation seems to indicate that "A Sound, a Song, and a Surprise" may have actually existed, not as an actual episode of the series but rather as a localized retrospective special a TV station cobbled together to celebrate the show's Grand Finale.
McLean Stevenson is supposed to have appeared in character as Henry Blake on The Carol Burnett Show (sitting in a rubber raft and shouting "I'm okay!"), the very next night after Henry was McLeaned on the show. However, there are no actual logs, data, or information to support that such a Carol Burnett Show appearance actually exists. Still, many fans swear to have actually seen it, and it was even supposedly posted on YouTube several years ago, only to be removed for copyright, which gives the appearance an Urban Legend status.
Many fans keep insisting that Radar kept appearing on the show less and less each season, to the point that his last full season on the show had him absent practically every other episode. This is certainly not the case at all. If one were to actually watch the series, and keep note, they will see that in Season Four, Radar appears in 23 out of 25 episodes; 23 out of 25 episodes in Season Five; 15 out of 25 episodes in Season Six; and 22 out of 26 episodes of Season Seven.
There's an urban legend that's been around for years that Mike Farrell bears animosity towards Wayne Rogers, the legend was even joked about on The Simpsons, where Homer reads a book by Farrell and remarks, "Wow, he really does hate Wayne Rogers!", however, there is absolutely no Real Life evidence that supports this story.
Similarly, some fans insist that Jamie Farr hates Alan Alda, but likewise, there is no Real Life evidence to support this.
The Woobie: Pretty much everyone was this at least once. Yes, including Frank.