"Who cares about decent? The game, Mrs Hudson, is on!"
Adorkable: When John arrives at 221B while Sherlock's parents are there, Sherlock's attempts to get them out and his attempt at casualness afterwards are hilariously awkward.
Taken up to Eleven, in "The Sign of Three", both as John's best man, and the de facto wedding planner.
Addiction Displacement: He outright admits he solves crimes as an alternative to getting high in "His Last Vow".
Allergic to Routine: Sherlock has a need for intellectual stimulation that strongly brings to mind a drug addict's desire for the stimulant of their choice, and repeatedly goes to dangerous lengths in order to avoid becoming bored - a trait he shares with his arch-nemesis, Moriarty. However, possibly as a means to complement Sherlock, this particular version of John Watson is heavily hinted to be an adrenaline addict and a thrill-seeker.
All of the Other Reindeer: In addition to being hated by pretty much the entire police force sans Lestrade, in "The Blind Banker", it is revealed that all his classmates hated him back in school (specifically university) too.
Ambiguous Disorder: Sherlock's behavior alternates from episode to episode between classic Asperger Syndrome, (difficulty understanding others' emotions, abnormally intense interests, idiosyncratic language) and classic sociopathy (disinhibition, lack of empathy, manipulation of others). John puts forth the former as a diagnosis, Sherlock insists it's the latter. There's a moral dimension to which way one interprets the ambiguity, as an autistic individual is more likely to be able to learn acceptable social interaction than a sociopath.
Lestrade: I suppose he likes having the same faces back together. It appeals to his... his... John: [snarkily] Aspergers?
The sociopathic tendencies predominate in A Study in Pink (taking inappropriate pleasure in horrific but novel crimes), The Great Game (shamelessly manipulating everyone around him, including John), and The Hounds of Baskerville (pursuing his goals without concern for the impact they will have on others).
Sherlock behaves more like a high-functioning autistic in A Scandal in Belgravia (when he seems genuinely confused by Irene's complex feelings for him) and The Sign of Three (when he can't understand why everyone has started crying in the middle of his best man speech).
The normally calm Sherlock doesn't take anyone hurting or insulting Mrs Hudson well. He throws the CIA agent in Scandal out a second-story window... five times... for touching her.
Don't mess with John, either. In The Empty Hearse Sherlock throws himself into a fire, and pulls John out with his bare hands. In His Last Vow, Sherlock murders Magnussen when he realizes that it's the only way to save Mary (and by extension, John) from the information Magnussen was using to blackmail her. He seems fully prepared to go to his death as a consequence of doing so.
Break the Haughty: The plot of "The Reichenbach Fall", where Moriarty uses Sherlock's jerkass pride in his work to slowly destroy the detective's life.
Brilliant, but Lazy: Zig Zagged Trope. If he thinks it's worth his while he'll run several blocks, break into private property, or lie and cheat to get information. If he doesn't, his level of laziness has to be seen to be believed:
In "A Study in Pink", won't lift his hand about three inches to grab the phone John offers him, forcing John to actually place it in his palm.
In "The Great Game", while fiddling with instruments, Sherlock asks Watson to hand him his phone, which is in his jacket. The one Sherlock's wearing.
In "A Scandal in Belgravia", gets John to Skype him a view of a crime scene because he doesn't want to get out of bed. Then can't be bothered to get dressed when summoned by the Queen.
Brutal Honesty: Sherlock's M.O. Used for both comedy and drama: one time he might humorously extort someone with sensitive information, while another John might chew him out for being rude and tactless.
Celibate Hero/Celibate Eccentric Genius: Sherlock considers himself married to his work, though that doesn't stop an intense - but brief - relationship from blossoming between him and Irene Adler in A Scandal in Belgravia, the exact romantic/sexual nature of which is not discussed; and then there's the Ho Yay between him and John Watson that certain fans claim to see all over the place (and which is occasionally referenced in-universe to John's annoyance).
Steven Moffat: It's the choice of a monk, not the choice of an asexual. If he was asexual, there would be no tension in that, no fun in that – it's someone who abstains who's interesting. There's no guarantee that he'll stay that way in the end – maybe he marries. Mrs Hudson. I don't know! (The Guardian, Jan 20th, 2012)
Moffat posits in the same interview that Sherlock dismisses the charms of women because he finds them a distraction, and that he would not be living with a man if he fancied men (because it would also be a distraction).
Cumberbatch weighed in on the matter to the blog Zap2It:
Benedict Cumberbatch: For me, Sherlock's not gay. He's not straight, necessarily. He has a sexual appetite, but it's entirely swallowed by his work. He doesn't have time for it.
Magnussen's "file" reveals that he has a porn preference. It's apparently normal.
Cloud Cuckoolander: Owing to his not always paying attention to the world. In spite of his intelligence, he doesn't know who the Prime Minister is and even forgets that England has a queen instead of a king- something he used to know.
Consummate Liar: Demonstrates several times that he is a rather convincing actor, pretending to be various roles as the situation requires. At one point he's so convincing he even fools the audience for a bit, crying and breaking down before laughing his arse off that John fell for it.
Crazy-Prepared: Had 13 possible plans to escape Moriarty on the rooftop. Faking his death was one of them, although it's implied that it was a last-ditch option.
Creepy Good: Owing to his sociopathic behaviour, even after it gets toned down significantly.
Deadpan Snarker: Being a self proclaimed high functioning sociopath may make you seem like a massive jerkass, but Sherlock shows how brilliant his wit is.
Distracted by the Sexy: Irene Adler has this effect on him, to the extent he noticeably stumbles over his words at one point and unwittingly foils a highly top secret and clandestine government plan, all in an effort to impress her.
During "The Sign of Three", whilst working out a case in his head, he's briefly gets distracted by the mental image of (a very naked) Irene Adler, when musing about the very few people aware of John's Embarrassing Middle Name.
Ditzy Genius: Invoked. Sherlock only keeps important information in his "mental hard drive," which does not include tact, common sense or heliocentrism. He even deletes stuff he used to know, such as there being a queen of England as opposed to a king.
Driven to Suicide: Appears to jump off a building to his death at the end of Series 2. Subverted soon after, when it turns out he faked his death instead.
Embarrassing Middle Name: Inverted. Turns out his first name is actually William. Granted, it's a lot less catchy and unique as "Sherlock".
Epic Hail: Sherlock's solution to getting the police to arrive quickly is to casually fire a gun into the air!
Faking the Dead: Faked his own death at the conclusion of "The Reichenbach Fall" to save his friends.
Fatal Flaw: His obsessive curiosity and constant need to not be bored leads him to irrational or cruel behavior that damages his relationships with his friends and sometimes even leads him to put his own life in danger.
Attempts by his parents to socialize him and Mycroft with other children to make friends failed, miserably. Both Mycroft and Sherlock scoff at the idea years later.
In Series 3, spending most of his development years with Mycroft is implied to have left a negative effect on his personality.
Until he met other children he always assumed he was an "idiot" due to only having Mycroft as a companion.
His mother by his own admission "has a lot to answer for" in regards to how her children turned out.
The death of his dog Redbeard hit him hard.
Friend to All Children: In "The Reichenbach Fall", he's very concerned about finding the kidnapped children and is very disturbed when they react in fear at seeing him. In "The Sign of Three", he befriends Archie due to their mutual passion for bizarre murders.
Friendless Background: It's strongly implied that John was Sherlock's first real friend. In A Study in Pink, both Donovan and Mycroft point out that Sherlock isn't the kind of person who make friends.
Glad He's On Our Side: His sociopathy, his despising being bored, and his being Not So Different from Moriarty are frequently brought up, as well as how awful of a prospect it would be if he stopped helping the police and ended up committing crimes for thrills himself.
Good Is Not Nice: As he tells Moriarty in "The Reichenbach Fall", "I may be on the side of the angels, but don't think for one second that I am one of them."
Grammar Nazi: Deliberately corrects the grammar of a prisoner in Minsk at the start of "The Great Game" to make the man confess to murdering his girlfriend.
Gray Eyes: Benedict Cumberbatch's glasz eyes can appear icy blue, grey or even slightly green depending on how a scene is lit. This is especially noticeable during his phone call with Mycroft in The Sign of Three, as he paces through several different lighting angles.
Guile Hero: Most of his fights are won through pure observation and intelligence.
Heroes Love Dogs: As a child he had a beloved pet dog named Redbeard who had to be put down. It's still a touchy subject for Sherlock well into adulthood.
Appears to be struck by one twice in "A Scandal in Belgravia". Firstly, he drifts trance-like into Baker Street after the revelation Irene Adler is, in fact, alive. Later, he seems stunned into inaction for a while once he realises that he has fallen for the oldest trick in the book.
Freaks out in "The Hounds of Baskerville", when he experiences fear and doubt for likely the first time in his life.
Played with in "The Sign of Three" where, after being asked to be John's best man, he stared at John for what is implied to be at least five minutes
Between the revelation of the Appledore vaults and the arrival of the choppers in "His Last Vow," Sherlock is practically catatonic.
Hypocritical Humour: During series three, episode three. He comes back to 221B and realizes that Mycroft is inside because the door knocker is straight, and says that he's OCD and straightens it without even realizing it. He then makes it crooked. Watson asks why he did that, and Sherlock's response is a genuine "Did what?"
I Want My Beloved to Be Happy: Sherlock seems quite melancholy that Molly has moved on from her crush on him to get engaged, but he wants her to be happy. Not that her engagement works out, anyway.
In a platonic version with John. By the time of "Sign of Three" Sherlock is well aware that things will be different with him and John since John now has a wife and unborn child to care for, but this doesn't stop Sherlock from doing whatever he can to protect the couple and their happiness.
Iconic Outfit: The deerstalker gets this treatment in-universe, to his exasperation.
Sherlock: Why is it always the hat photograph?
Not to mention his popped-collared Badass Longcoat and Scarf of Asskicking, which are iconic in-universe and out — to the point that when Lestrade asks him not to be as... Sherlock... as he usually is, he just un-pops his collar.
Sherlock: That's the frailty of genius, John. It needs an audience.
Goads Lestrade into admitting that Scotland Yard needs his detective skills.
Explains every step of his deductions to John to prove they weren't a "trick".
Plays the Cabbie's suicidal Battle of Wits just to prove how clever he is.
Screws with Sebastian in "The Blind Banker" after Sebastian remarks that Sherlock's fellow students at university hated him.
Is rather surprised to hear John call his deductions "extraordinary."
Sherlock: That's not what people normally say. John: What do people normally say? Sherlock: "Piss off!"
May stem from his childhood with Mycroft, in which Mycroft's brilliance led them both to believe that Mycroft was "the smart one" and Sherlock was stupid, until they tried making "friends" with normal people.
Called "Hatman" by the press, due to wearing a deerstalker to hide his face.
"The Reichenbach Hero" for his most famous case to date.
"Sir Boast-A-Lot", which Moriarty alludes to while telling a fairytale. According to Irene, he also calls him "the virgin".
"Shag-A-Lot Holmes" by a paper who got a falsified scoop from the woman Sherlock was temporarily engaged to.
Insufferable Genius: He really can't help himself, not even after getting tossed out of a courtroom where he's the star witness and into a prison cell for showing off.
Intelligence Equals Isolation: Zig-Zagged. It's hard to say what came first, Sherlock's incapacity of social interaction, or his aversion of it. Although Mycroft seems to have encouraged distance to others, his friendship with John proves that he is neither above nor averse to relationships with other people as long as it does not hinder his work.
It's All About Me: It's entirely likely that Sherlock didn't know the earth revolves around the sun because he thinks that it actually revolves around him.
Sincerely apologizes to Molly after offending her in "Scandal"; John is visibly shocked.
Fantasizes about all the ways he could kill the CIA operative and then throws him out a second story window multiple times after the man harms Mrs. Hudson later in "Scandal".
Fakes his own death to protect Watson, Mrs. Hudson and Lestrade in "The Reichenbach Fall". Note that he does this by jumping off of a building, likely using the same deductions he used to throw the CIA operative repeatedly out a window with non-lethal results on a larger scale. But he still fakes his death to save those he cares about by jumping off of a building, which still has the somewhat expected results of just nearly killing him instead.
Acknowledges this himself in his best man speech at John's wedding, calling himself an "arsehole" but saying that John makes him better. As "The Last Vow" shows, he'll get himself exiled on a suicide mission for his sake.
Knight Templar Best Friend: When it comes to John and Mary's happiness. Unbeknownst to either of them, after deducing that one of her former boyfriends invited to the wedding was still madly in love with her, he took matters into his own hands. He confronted him with the evidence, announced that he'll be downgraded to casual acquaintance and only allowed three visits per year (with John's supervision) and that he will be monitoring him closely.
Admits it during a conversation with a boy in John's wedding.
Sherlock: Grown-ups like that sort of thing.
Sherlock: I don't know. I'll ask one.
Also from John's wedding:
Sherlock: You'll be great parents. You've had lots of practice with me.
In His Last Vow, after John has found him in a drug den.
Sherlock: I'm undercover.
John: No, you're not.
Sherlock: Well, I'm not NOW!
When Mary shoots him, he temporally regresses into a child inside his mind palace, when looking for a way to maximize his survial chances.
A Man Is Not a Virgin: Averted. Sherlock claims in the very first episode that neither girlfriends nor boyfriends are his area and he considers himself married to his work. In Season 2, it's explicitly stated that he is a virgin. But in response to speculation about Sherlock's asexuality, creator Steven Moffat has noted that he sees Sherlock as a heterosexual with a "monk-like devotion to celibacy," while hinting that said devotion may change as the series progresses.
John is in disbelief that Sherlock has apparently never had a "girlfriend, boyfriend, a relationship of some kind, ever."
Moriarty's nickname for Sherlock is "The Virgin".
Even Mycroft mocks his brother:
Sherlock: Sex doesn't alarm me. Mycroft: How would you know?
In "His Last Vow", Sherlock seduces Janine and lives with her as his "girlfriend" for some time in order to get close to Magnussen. When she finds out that it was all faked and goes to confront him, one of her complaints is that "...just once would have been nice."
Sherlock: I was waiting until we were married. Janine: ...which was never going to happen!
Manipulative Bastard: Tricks victim's distraught family members into giving him information, lies his way into locked apartments, and so on.
A particularly egregious example is on his return in the third series. In the Underground below parliament he leads John to believe that he can't stop the bomb, he hasn't called the police, and they will surely die He begs for forgiveness, complete with quavering voice and tears. And having received John's forgiveness as he reconciles himself to their deaths Sherlock laughs and turns it into a Did You Actually Believe? moment. .
Another brutal example comes from "His Last Vow," when he seduces and becomes engaged to Janine in order to get access to her employer, Magnussen.
Married to the Job: Celibacy aside, this is the reason he gives for why dating (or human social interaction in general) isn't "his area". You can count the number of people close to him in any sense on one hand.
Morality Pet: John, Mrs Hudson and Molly all serve to keep Sherlock grounded.
Motor Mouth: Whenever he goes into a Sherlock Scan. We're talking supersonic or even relativistic speeds here. It's entirely possible that Cumberbatch doesn't need to breathe; for example, just listen to his explanation of John's phone or much of "Hounds of Baskerville". And whenever IreneAdler is around he somehow manages to go even faster.
In one interview, Gatiss comments on the extreme length of the deduction in Baskerville; apparently, on Cumberbatch's script he actually wrote "Sorry, Benedict" next to it.
Must Have Nicotine: It's impossible to sustain a smoking habit in London nowadays, so Sherlock confines himself to patches. It just might end up being "a three-patch problem".
Goes absolutely haywire in "Hounds of Baskerville" when he's detoxing, turning the entire flat upside down and outright begging John to give him a cigarette.
Noted in "The Sign of Three" where a patch can be seen under his shirt.
Not even hiding the fact that he's smoking and doing other drugs as of "His Last Vow."
Noble Demon: Freely admits that he's a High-Functioning Sociopath.
No Social Skills: Insults his friends, gets on trains covered in pig's blood and holding a harpoon, and visits Buckingham Palace practically naked.
It wasn't until "The Sign Of Three" that he realized that John actually thought of him as his best friend. And John had to tell him.
Odd Friendship: On the face of it, Sherlock and John have absolutely nothing in common. However, their shared Allergic to Routine tendencies end up making them rather inseparable.
One-Man Army: At the end of "A Scandal in Belgravia", he wipes out an entire terrorist cell single-handedly, armed only with a scimitar.
Pet the Dog: His apology to Molly for verbally tearing her apart on Christmas, complete with a sincere kiss on the cheek.
Sherlock: Merry Christmas, Molly Hooper.
Prayer Pose: Sherlock uses this pose frequently, but as a sign of concentration while he's thinking, rather than any form of actual prayer or supplication. The books often describe Sherlock as sitting with his hands steepled below his chin.
Sherlock Scan: Demonstrated brilliantly. Even John admits to being impressed.
Shipper on Deck: For John/Mary. He plans their wedding, scares off Mary's ex-boyfriend and breaks out of hospital with a gunshot wound in order to play marriage counselor to them.
Shoot the Dog: The inevitable result of revealing to a high-functioning sociopath that killing you is the only way to save his best friend's marriage (and his brother's ability to remain unbiased).
Slasher Smile: Sports an epic one when he's dealing with David in "The Sign of Three".
David: They're right about you. You're a bloody psychopath!
Sherlock: High-functioning sociopath. With your number. *grins*
The Sociopath: Played with regularly. Sherlock has all the classic signs of a fictional sociopath: a general lack of empathy; self centered behavior; total disregard for laws; regular use of fake charm, lies and manipulation to achieve his goals; he even goes so far as to call himself one. Ultimately subverted however, since when push comes to shove Sherlock really does care about his friends. It's suggested that Sherlock has tried to mold his mind into sociopathic thought patterns in order to function better as a detective.
The Spock: John even calls him "Spock" in "The Hounds of Baskerville".
Sticky Fingers: John's laptop, Lestrade's warrant card, an ashtray from Buckingham Palace, and Mycroft's clearance ID.
The Stoic: Shows little emotion most of the time, especially compared to those around him at crime scenes or during an investigation.
Not So Stoic: Whenever John is genuinely threatened or in danger. Stick him in a bonfire, strap a bunch of bombs to him or point a gun at the good doctor's head, and Sherlock's cool mask will evaporate in two seconds flat.
Also two moments in "The Great Game": When the elderly blind woman begins to talk about the soft voice of the person who kidnapped her, Sherlock frantically warns her against it, knowing that the kidnapper will likely detonate the bomb he has strapped to her as punishment, which he does. Later on, when attempting to solve the riddle of how the painting was faked before the kidnapper blows up a child, he's clearly freaking out. Despite his supposed interest in puzzles over people, the prospect of these two lives being lost deeply disturbs him.
When Mrs. Hudson is taken hostage, he rescues her, has Watson take her downstairs... and then proceeds to beat the crap out of her attacker and toss him out the window. Repeatedly.
Is visibly shaken after his "encounter" with the titular creature of ''The Hounds of Baskerville", and even admits his fear to John.
"The Reason You Suck" Speech: Delivers one to himself in his best man speech at John's wedding, pointing out the sheer number of flaws and personality quirks that make him a terrible person and friend, but which John's patience has helped him to better overcome.
Too Clever by Half: His need to be challenged gets the better of him sometimes and he ends up doing things any normal person would back the hell away from.
Took a Level in Kindness: Over the course of the series undergoes this due to John's influence, which he admits and credits him for Series 3, by which he's considerbly nicer than he use to be.
Trademark Clothing: His coat, he makes a point asking for it in "The Empty Hearse". His blue scarves count as well.
Tranquil Fury: You'll never realize he's angry until after he's beaten the crap out of you.
Or shooting you.
Troll: Even when he's not bored out of his mind he can occasionally be an ass to get a rise out of people. Best example is him fooling John into thinking that they're both about to die since he can't disarm the bomb and he hasn't called the police just to watch him freak out.
The Unfettered: Accused of being psychopath by most of Scotland Yard. Also has no problem ignoring 90% of the laws if it'll help him solve a case or help a friend. In order to protect John and Mary in "His Last Vow" he murders Magnussen in front of John, Mycroft, and three armed policemen.
The Un-Smile: Invoked to scare the hell out of David. To the audience it's equally hilarious and unsettling.
Adorkable: Doctor Watson. Martin Freeman's support of Woolly Hat Day.
Allergic to Routine: As much as he complains about Sherlock's behavior, there's nothing in theory to stop him simply walking away - except, as Mycroft points out, he's nearly as big a danger-junkie himself.
Aloof Big Brother: Is somewhat distant from his sister, Harry, because he doesn't like her drinking.
Badass: We know (from a blog comment by Bill Murray, the nurse) that he's the recipient of at least one medal, and Sherlock refers to him as a "war hero" during the taxi drive to Brixton.
Badass Adorable: Whether it's shooting a guy dead under improbable odds, sassing back criminal masterminds who've kidnapped him or ordering around CIA agents who have a gun to the back of his head, chances are he'll be doing it in a cardigan. Also is strongly implied to be one of those people who start celebrating Christmas in October.
Blood Knight: John isn't traumatized by combat so much as he misses it.
Sherlock himself comments on this tendencies after Mary is discovered as a rogue intelligence agent and John asks whether or not everyone in his life is a 'psychopath'.
Sherlock: You were a doctor who went to war. You're a man who couldn't stay in the suburbs for more than a month without storming a crack den and beating up a junkie. [...] John, you are addicted to a certain lifestyle. You're abnormally attracted... to dangerous situations and people.
Boring Yet Practical: Prefers to use diaries and cameras to record data instead of bizarre memory techniques. Also prefers to call the police using a phone instead of a gun, and would like Mycroft to call him instead of kidnap him.
"You know ... I've got a phone. I mean, very clever and all that. But you could just phone me. On m' phone."
Distracted by the Sexy: Frequently. At Buckingham Palace, he gets so carried away imagining that he nearly drops the fine china.
Embarrassing Middle Name: Hamish. He dislikes it so much that Sherlock couldn't goad him into divulging it and only found out by looking at his birth certificate. His middle name becomes a plot point in "The Sign of Three".
Foil: To Sherlock. Pretty much an obligatory aspect of his character.
Incompatible Orientation / Married to the Job: He started to catch this from being around Sherlock; none of his girlfriends were able to put up with their adventuring for long. Fortunately, Mary adores Sherlock possibly even more than John does - but it's still unlikely they would have got to the point of marriage had Sherlock not been off the scene for a couple of years.
Jeanette: My friends were wrong, you know. You're a great boyfriend - and Sherlock Holmes is a very lucky man.
In Harm's Way: When your best friend is a crime solving sociopath, and your wife is a retired professional killer, you really have no excuse.
Magnetic Hero: For someone who doesn’t go out of their way to make friends, people seem to quickly take a liking to him. At any rate, he’s a far more likable hero than Sherlock.
Minored in Asskicking: He's generally known for his equanimity, but if you make him angry, you'll know about it.
Mistaken for Gay: By Mrs Hudson, Irene Adler, and several of his short-lived girlfriends. At least until he meets Mary.
Morality Pet: For Sherlock, letting him know whenever he's said or done something "not good".
Mysterious Middle Initial: In "A Scandal in Belgravia", John H. Watson finally reveals his much-speculated upon middle name: Hamish.
Which of course lines up with Conan Doyle's canon. For even more speculation, see the pre-season-two debate on DI Lestrade's first name. Conan Doyle only gave an initial (G) which BBC expanded to Greg.
Nerves of Steel: You'd be amazed by how much he goes through completely terrified and yet keeps his calm no matter what. It's telling that the only time we really see him panic is when Sherlock drugs him with a chemical specifically designed to cause irrational levels of fear, and even then he keeps his head enough to get to the safest place possible and continually report what's going on.
There's a Freeze-Frame Bonus in The Blind Banker where you can see his resume, which says he's a trauma surgeon. That makes him combat trauma surgeon and people don't get that job without Nerves of Steel on several levels.
Nothing Exciting Ever Happens Here: A variant; John says "Nothing ever happens to me" to his psychologist's suggestion that he blogs everything that happens to him. And then a couple of scenes later, he meets Sherlock...
Only Sane Man: Frequently. Especially when Mycroft and Sherlock are yelling at each other and playing tug-of-war with a bedsheet protecting Sherlock's modesty. In the middle of Buckingham Palace.
Lampshaded dramatically in "His Last Vow" when Sherlock points out John is attracted to unstable, dangerous people, pointing out himself, Mrs Hudson (who formerly worked for a drug cartel and was an exotic dancer) and his own wife, who was a CIA assassin.
Pintsized Powerhouse: As seen in "A Scandal in Belgravia", where Sherlock learns it's not a good idea to hit him. John hits back. Hard.
John: (has Sherlock in a headlock) You ought to remember, Sherlock, I was a soldier! I killed people!
Throwing Off the Disability: His limp is psychosomatic, meaning that he can lose it when he forgets about it. In fact, he was actually shot in the shoulder, meaning that his leg is completely fine.
Vitriolic Best Buds: Him and Sherlock. Hardly a moment passes when they aren’t snarking at each other.
Undying Loyalty: Basically spits defiance when Mycroft asks him to spy on his brother on his behalf, something that he knows could end very badly for him. This is after he's known the man for 24 hours and has gone to one crime scene with him.
Unfazed Everyman: From who else but himself? He adjusts remarkably quickly to the weirdness that comes with being Sherlock Holmes's sidekick.
John: We've only just met.
Mycroft: And since yesterday you've moved in with him and now you're solving crimes together. Might we expect a happy announcement by the end of the week?
Weirdness Magnet: Sherlock implies he's naturally attracted to this, although only unconsciously. Mary agrees.
What the Hell, Hero?: If Sherlock's getting one of these, chances are good that John will be the one lecturing him, and chances are that he'll be the only one Sherlock will even try to listen to.
With Friends Like These...: With Sherlock and cranked Up to Eleven in "The Hounds of Baskerville" when Sherlock drugs John and then locks him up in a lab to conduct an experiment that involved scaring the crap out of John, a war veteran who still suffers from nightmares and flashbacks related to the battlefield. It's surprising that John didn’t at least take a swing at him afterwards.
Wouldn't Hit a Girl: Violence against women seems to bother John. He's notably guilty about Soo Lin's death in "The Blind Banker", becomes noticeably distressed at the crying woman in "The Great Game", and while he had no problem punching the Superintendent of Scotland Yard for calling Sherlock a "weirdo", he ignores Sally Donovan rubbing it in that Sherlock was not to be trusted.
Camp Straight: Keeps up his Camp persona after revealing his identity to Sherlock. Also delights in flirting with him, calling him "sexy" and "honey". As always, it's hard to tell what really motivates him.
The Chessmaster: In Series One, he's behind every case Sherlock investigates. In Series Two about the only one he wasn't involved in was an actual accident.
Consummate Liar: To the point where he can claim to be the former host of a children's TV show, and have an astounding amount of evidence to back it up.
Dangerously Genre Savvy: As "Scandal" shows, if it comes down to a choice between baiting Sherlock Holmes and his actual job, he'll pick the job. After all, crime is a heavily trust-based business.
In "The Reichenbach Fall", he plays — and wins — Gambit Roulette with both Holmes brothers and forces Sherlock to fake his own suicide or risk John, Lestrade, and Mrs. Hudson's deaths. Although in Season 3, Sherlock claims he and Mycroft were playing Moriarty all along.
Driven to Suicide: Zig-zagged. Looks suicidal when he realizes that in destroying Sherlock, he's actually won, and now has nobody who will pose a challenge to him anymore. Then changes his mind and says he'll manage. Unfortunately Sherlock then convinces him that as long as Sherlock has Jim alive, Sherlock can also stop Jim's plan. Moriarty promptly shoots himself in the head to make sure Sherlock can't beat him.
Possibly subverted at the end of "His Last Vow".
Evil Counterpart: To Sherlock. In this version, he lists his occupation as "Consulting Criminal", and his Insufferable Genius tendencies are played up just as much as Sherlock's. His goal, as it turns out, is to find a perfect counterpart — someone who is him. Sherlock indulges him, in the end, and admits as much. He may well have faked his own suicide, to boot.
Foe Yay Shipping: In-universe, no less, judging by one of the members of Sherlock's fanclub who puts forward the theory that Sherlock and Moriarty faked their deaths to run off into the sunset together!
Knight of Cerebus: The series was never the most lighthearted, but there was plenty of humour. When Moriarty enters as an indirect antagonist, the death toll escalates and the show gets darker. When he appears in person, things get seriously disturbing.
Large Ham: His high-pitched voice and psychopathic mannerisms make him constantly appear on the edge of psychotic madness. He also changes his tone of voice and his mannerisms about every other line, rapidly going through affected personas and acting styles just to mock Sherlock. He's always hammy, though.
Thanatos Gambit: "The Reichenbach Fall". To ensure that there is no way for Sherlock to stop his plan, he kills himself, thus forcing Sherlock to commit suicide to protect his loved ones.. apparently all For the Evulz.
My Death Is Only The Beginning: "His Last Vow" ends with his image appearing on every screen in the United Kingdom, suggesting he had plans in place even in the event of his death, if he even died at all.
The Unfettered: Ultimately a deconstruction. Having absolutely no empathy and no limits, Jim's one and only concern is to try and stave off his endless boredom... even if that means putting his own plans and well-being at risk to do it. Best illustrated in the second series finale where Moriarty gleefully shoots himself in the head for no reason other than he thinks it's the best way to "win" his game with Sherlock.
Unwitting Pawn: Makes one out of Molly Hooper, Sally Donovan, and the entire British legal system and tabloid press in "The Reichenbach Fall". Such is his Manipulative Bastardy that he even makes pawns out of the Holmes brothers themselves. Although Sherlock claims in season 3 that Moriarty was the one being played all along.
Victory Is Boring: As Sherlock points out, there is nothing that Moriarty can't already steal or buy. No problem presents a challenge for him. And Jim absolutely can't stand it.
Would Hurt a Child: He threatens to blow up one in "The Great Game". In "The Reichenbach Fall", he poisons two more and almost kills them, as they could play into his plans well.
You're Insane!: Sherlock says this to Moriarty in "The Reichenbach Fall".
"Do you know the problem with a disguise, Mr Holmes? However hard you try, it's always a self-portrait."
Adaptational Badass: In the original stories, Irene Adler's impressive feat was simply seeing through Holmes' ruse and having the good sense to skip town while she has the chance. Here, she manages to con him into decoding top-secret, vital information which she then passes along to Moriarty, ruining Mycroft's day. It takes a last-second epiphany for Sherlock to recover himself and make up for his own royal screwup.
Big Bad Wannabe: For all of Irene’s cleverness, it’s still clear that she wouldn’t have gotten away with as much without Moriarty’s assistance.
Bitch in Sheep's Clothing: She may not have been a sweetheart when she was introduced but by the time the episode ends, it’s revealed that she’s complicit in terrorist plots and Moriarty's willing accomplice.
Bi the Way: She's been in relationships with both men and women prior to meeting Sherlock.
Brains and Bondage: A dominatrix who caters to the highest echelons of society. One of very few people to get several over on Sherlock Holmes.
Dramatic Irony: Spends most of "Scandal" trying to exploit Sherlock's "emotions" as well as his pride and in the end her own feelings for Sherlock turn out to be her undoing.
Easily Forgiven: She was perfectly willing to extort the British government for millions, enlist the skills of a psychopath, aid in a terrorist plot, and manipulate and betray Sherlock, yet she still gets saved by Sherlock in the end and lives without any apparent consequences or moral development.
Fun with Subtitles: When Sherlock does his trademark scan, a subtitle floating beside the clue says what he's noticed. When he first meets Irene, all his scans get is "???????".
Jerk with a Heart of Jerk: Let's be honest, whether she has feelings for Sherlock or not, it still doesn't stop her from treating him terribly or excuse her for working with Moriarty. She's made it pretty clear all through that episode that her self-interest comes before anything else.
Karma Houdini: For all the havoc and damage she caused, she still gets to survive in the end.
Laser-Guided Karma: She does everything she can to exploit Sherlock’s naivete when it comes to sex and intimacy but in the end her own feelings for him prove to be her downfall. Verges on Dramatic Irony.
Mata Hari: One of her many tricks for stealing blackmail material.
Single-Target Sexuality: Caters to both male and female clients, claims to self-identify as being gay, yet the only man (or indeed anyone) she actually shows any serious interest seems to be Sherlock. Her chosen password is particularly telling.
Woman Of Wealth And Taste: The phone everybody was fighting for in "A Scandal in Belgravia" was a Vertu Constellation Quest smart phone, with a price tag of £17,300. There was more than one reason she was fighting tooth and nail to get it back.
Achilles' Heel: Magnussen stores all the information about his victims not on a computer, which would be hackable, but in hard copy form in a vast underground vault underneath his high-security home. Only he has access to it, and he doesn't let anybody in. . . . Except that he doesn't. There is no such vault. He just remembers it all. As a result, Sherlock, being a self-described high-functioning sociopath, is able to eliminate Magnussen as a threat by shooting him in the head.
Adaptational Badass: His literary counterpart was content blackmailing England's nobility and gentry, specifically ladies, who were either married or engaged. Here he's blackmailing world governments, and instead of keeping all of his information in a locked safe, he keeps it all in his own head.
Always Someone Better: Sherlocks' hatred of him is exacerbated by the fact that Magnussen is genuinely smart enough to outwit him.
Arch-Enemy: Sherlock mentions that Magnussen is the most dangerous threat he's faced up to that point and nobody's ever made his stomach turn quite like Magnussen. At least Moriarty has theatricality and psychosis as an excuse. Magnussen is simply scum.
Boom, Headshot: Sherlock shoots him in the head after he makes it clear that if he dies, his information goes with him.
The Bully: What he basically is, and the specific reason Sherlock hates him as he picks on people for being different, hinting at a bit of bullying in Sherlock's own past.
Card-Carrying Villain: To the people he's blackmailing. In public, he presents himself as a simple businessman.
Defied at the end, though- he mocks Sherlock and John precisely for treating him like some kind of villain. He seems to honestly believe that he isn't a villain due to some Insane Troll Logic like, for instance, the fact that he technically hasn't killed anyone (even though he has ruined several lives and puts others in mortal danger, both for his own amusement).
Dangerously Genre Savvy: He keeps all his information in an underground vault in hard copy, because computers are hackable. Taken further when we find out there is no vault. He's able to memorizeeverything, by having his own version of Sherlock's mind palace.
Evil Counterpart: Another one to Sherlock. Like Sherlock, he's a genius who stores vast amounts of information in his head via the Mind Palace technique. This is the secret of his serial blackmailing. He doesn't need to store the information corporeally or digitally. He's basically Sherlock's logical side, if taken to a cold, logical extreme.
Like Sherlock, Magnussen specializes in uncovering secrets and solving mysteries, but while Sherlock uses it to put evil away and better society, Magnussen uses it as power to assert his dominance over people and countries.
He is arguably more the evil counterpart of Mycroft. Both have extensive influence over governments, both have direct yet ethically-questionable access to leaders of Britain, both are more chessmasters than trickster, and both are strongly implied to actually be smarter than Sherlock (and both definitely like reminding him of it). Its strongly implied that Magnussen has clashed with Mycroft before and has found a way to blackmail or control him which may be threats against Sherlock and at one point Sherlock tries and fails to bribe him with Mycrofts laptop, because Magnussen craves the information on it. In the original stories Sherlock muses that if Mycroft had the inclination he could easily become the most successful criminal the world had ever seen- Magnussen could be read as an attempt to see if that is true.
Evil Cannot Comprehend Chaotic Jerkish Good: For all the ways that he managed to outwit Sherlock and take advantage of the fact that John is Sherlock's pressure point, he was apparently unaware of how far Sherlock would go to protect John.
Also, for all the truly vile and horrible things he does every single day, he scoffs and laughs at the idea that he is actually the bad guy.
Evil Is Petty: Mainly because of all the information he has on people, he fully believes he can do whatever to whomever he wants. In fact this seems to be his main motivation.
He licks Lady Smallwood's face after declaring he can ruin her husband.
He pisses in 221B's fireplace, and when he wipes his hands, he throws the towelette on the floor.
He picks up and eats an olive off Sherlock's pasta meal and cleans his fingers with Sherlock's drink.
Sadist: Absolutely revels in the power his information, influence and public standing gives him over other people- to the point of forcefully licking the arm and face of a government minister or pissing in Sherlocks' fireplace, just because he can.
Shadow Archetype: If Moriarty is the more chaotic, wild counterpart to Sherlock, Magnussen is Sherlock to his absolute coldest depths.
He is also a more smug, sadistic, and unprincipled version of Mycroft, what the latter could be if he stopped caring about the defence of the realm and instead decided to rub its face in the mud.
Smug Snake: He considers John and Mrs. Hudson to be "unimportant".
All his information is memorized, so there's no hard copy of it. But he tells this all to Sherlock, thinking he got one up on him, which is a rare but severe miscalculation on his part. Sherlock has no problem putting a bullet in his brain when he threatens John and Mary's happiness.
Stat-O-Vision: His glasses show information useful for blackmail on anyone he looks at including their porn preference and "pressure points." It turns out that his glasses are completely ordinary and the information he sees is just his "mind palace." It still fits this trope, though.
Thou Shall Not Kill: Villainous version, and an extremely borderline case. He has no problem arranging for John to be put in a bonfire just to see how Sherlock would react...but says he had a man on-site who would have saved him had Sherlock not made it in time, so it doesn't really count. His final fate is to be on the receiving end of Sherlock defying this trope. Also, at least one of his blackmail victims committed suicide after he threatened them, and he doesn't give a damn.
Ungrateful Bastard: Mycroft has him under protection, yet Magnussen has no problem stealing data from British Intelligence if it gives him more power. But he's Genre Savvy enough not get caught doing it.
White Void Room: His "vault", which helps him in accessing his mind palace.
Jeff Hope (Phil Davis)
"It's not chance, Mr. Holmes, it's chess. It's a game of chess."
Alone with the Psycho: A variation. Sherlock actually volunteers to be alone with the psycho because aforementioned psycho's promised to tell Sherlock how he's been committing his murders.
Beneath Notice: As he says, nobody ever thinks about the cabbie. It's like he's just a back of a head. He's able to take advantage of his job to hide in plain sight and be inherently trusted by his victims.
The Dog Was the Mastermind: There was some subtle foreshadowing about what the character's profession was, but the character himself is never introduced, nor is he ever clearly seen onscreen, until the climax of his episode.
Driven to Suicide: It looks like this is what he does to his victims. It turns out he's forcing them at gunpoint to choose between two pills, one of which is poisonous.
Evil Old Folks: His exact age is unknown but he's definitely getting on in years.
Faux Affably Evil: His tone is certainly friendly and cordial, but the actual content of what he says shows him to be a pretty massive asshole.
Lack of Empathy: He doesn't seem particularly bothered by the fact that he has to kill people in order to secure money for his children. In fact, he seems to like killing and holds most people in contempt.
Love Makes You Evil: The entire reason behind his killings is because, once he's dead, there'd be no income to provide for his children. Moriarity acts as a "sponsor," paying him loads for each person he kills.
Manipulative Bastard: He's able to play on Sherlock's constant curiosity and desire for excitement to get Holmes to, not only go alone somewhere with him, but also to play the "game" even when there’s no reason for Sherlock to do so. His game also depends on manipulating people based on what he's deduced about them and what he believes they've deduced about him.
Never Suicide: The entire plot of his episode really. Though since these are "serial suicides" it's kind of obvious.
No Name Given: His name is only revealed in the credits, and even then his last name's not given.
Not Afraid to Die: Whenever he plays his "game" with his victims, there's a good chance he could die too but he just doesn't seem to care. Most likely it's a combination of this trope due to the knowledge he's dying anyway, and confidence that he'll always be able to outsmart his opponents.
Papa Wolf: The more people he kills, the more money Moriarty gives to his children.
Poisoned Chalice Switcheroo: His method of killing involves offering his victims a choice between two identical pills, one of them harmless, the other poisoned.
Serial Killer: He's murdered at least four people and he aims to take a fifth in Sherlock Holmes.
Smug Snake: While he is a very clever man, as proven by how he's managed to survive four rounds of his "game," his arrogance, cold-bloodedness and firm belief in the stupidity of everyone around him does little to earn anyone's admiration.
Starter Villain: He's the villain of the first episode of the series, and, while clever and dangerous enough to arouse Sherlock's interest, he's just the opening act for Moriarity.
Take a Third Option: If anyone tries to refuse his game, he offers them a bullet from his gun instead. Gun's a fake.
Worthy Opponent: While he talks about all his other victims as if they were idiots, he seems to hold Sherlock in some regard. Granted he still thinks Sherlock's not as smart as him, but he's conversational with him and even compliments Sherlock on the ideas Sherlock's put on his website.
Your Days Are Numbered: He has a life-threatening aneurysm, meaning he lives with the knowledge any breath could be his last.
Detective Inspector Greg Lestrade (Rupert Graves)
"Well, don't let it get to you, I always feel like screaming when you walk into a room. In fact, so do most people."
Demoted to Extra: In Series 3, the main focus is how John and Mary's marriage has changed they dynamic of the show. Lestrade's still in all the episodes but he doesn't do that much plotwise.
Distracted by the Sexy: Molly's Christmas dress in "Scandal" causes Lestrade to need to pick his jaw back up off the floor.
Donut Mess with a Cop: When Sally startles Lestrade in his office at the beginning of "Reichenbach", it's to find him with his feet up on his desk, classily stuffing his face with a doughnut and talking with his mouth full.
Hero of Another Story: Cast by Moffat and Gatiss specifically because Rupert Graves gave off this trope when he played the role.
Inspector Lestrade: Played with. He is, of course, Inspector Lestrade himself, and often acts as if he's only there so that Sherlock can tell someone "no, you're completely wrong," but most of the time he lends himself more to a Friend on the Force role.
Lawful Good: In-universe, while he briefly seems to contemplate that Sherlock might be a fraud, he shows up to speak to Sherlock first before returning with a warrant to arrest him. Even then, he warns Sherlock and John in advance, causing John to lampshade this.
Team Dad: Most notably in Many Happy Returns where he checks in on both Anderson and John with genuine concern. Also often talks to Sherlock like a stern father or authority figure.
Him being the only person (that we see) to hug Sherlock upon his return reinforces this.
Undying Loyalty: In "The Sign of Three", leaves an important case that has both plagued and infuriated him for over a year, leaving someone else to get the credit for the bust, simply because Sherlock texted him saying that he needed his help urgently because he was in trouble. Lestrade immediately calls for backup and storms over there... only to find that Sherlock was having trouble writing his best man speech.
Green-Eyed Monster: She appears more than a little resentful of Sherlock's abilities, especially when the media start painting him a hero.
Jerkass: Towards Sherlock. Sally rationalises her antagonism towards him as a being a result of Sherlock enjoying his work a little too much. She's notably much more personable toward Watson, encouraging him to leave Sherlock as it'll likely end badly for him. She doesn't really show these tendencies to anyone other than Sherlock, and might be closer to a Jerk with a Heart of Gold.
"Never mind that, we found the case! According to someone, the murderer has the case, and we found it in the hands of our favourite psychopath."
The Atoner: In "Many Happy Returns", he's come to regret the part he played in Sherlock's downfall, and is obessed with proving Sherlock's still alive to the point where he lost his job because of it.
Bad Cop/Incompetent Cop: It's unclear if he's actually good at his job or not, since all we hear is Sherlock trashing him. In the original pilot, Lestrade seems to treat him better.
Implied that he's not completely incompetent, considering Sherlock asks for him specifically in "Reichenbach" (despite reluctance in "A Study in Pink", which he claimed was because "Anderson won't work with me").
Beard of Sorrow: Has one in the minisode "Many Happy Returns" and in Season 3, due to guilt over the part he played in Sherlock's downfall.
Bullying a Dragon: Sherlock only has to sniff him to figure out he's having an affair with DS Donovan.
Butt Monkey: Sherlock can't stand him, and as such, treats him horribly.
"Anderson, don't talk out loud, you lower the IQ of the entire street."
Cassandra Truth: In "Many Happy Returns," he has tracked Sherlock's movement and come to the conclusion that he is alive and coming back. No one believes him (at least, Lestrade doesn't.)
Gratuitous German: Apparently knows enough to tell Lestrade and Sherlock that "Rache" is German for revenge.
With perfect pronunciation no less!
Lab Rat: An in-the-field version, as he's a crime scene tech.
My God, What Have I Done?: Implied to have one of these between Series 2 and "Many Happy Returns", over the role he played in Sherlock's downfall. Despite how much he hated him, Sherlock's death has weighed heavily on his conscience.
Sanity Slippage: Guilt for his part in Sherlock's death apparently lead him to become obsessed with the case, lose his job and concoct increasingly bizarre theories for how Sherlock is alive and how he faked his death. He's right of course, but no-one believes him. Even when Sherlock tells him how he supposedly did it, he immediately begins questioning the explanation and appears to go a little mad from the revelation. He does however get better, and get his old job back.
Always Someone Better: True to the books, he is smarter than Sherlock. In "The Empty Hearse," they reflect on how they thought Sherlock was stupid because, as children, they had no one to compare him to but Mycroft.
Ambiguously Gay: If you take Sherlock's "queen" joke at face value. He does have a few of the traits.
John Watson:(wondering what they're doing in Buckingham Palace) Here to see the Queen? (Mycroft walks in) Sherlock Holmes: Oh, apparently yes. (Sherlock and John giggle like children)
Though this could be more towards the statement of Mycroft being the government.
Ascended Extra: Originally just a cameo, Mycroft is central to most of the happenings of Series 2.
Big Brother Bully: Probably unintentional, but still present. Sherlock thought he was 'the stupid one' and Mycroft apparently did too, Mycroft in Sherlock's mind palace sits above him and judges him in the courtroom, and his stories to Sherlock as a child were about unworthy children being plucked from the earth, of which Sherlock was one. In Sherlock's own words, "He was a rubbish big brother."
Break the Haughty: Gets this twice throughout the series, due to his arrogance: Driving Sherlock towards Irene results in an anti-terrorist plot being compromised in "A Scandal in Belgravia. In "His Last Vow" he refuses to deal with Magnussen. Also he rather carelessly leaves his laptop out in the open at his parents home, which Sherlock takes in an attempt to bargain with Magnussen. When the deal goes sour, Sherlock ends up killing Magnussen.
Brilliant, but Lazy: Typical for the character, he can even outdo Sherlock when it comes to deductions, but he dislikes legwork.
Defrosting The Iceman: We get to see a more human side of Mycroft in Series 3, one who does such prosaic things as play board games, lament "the horror" of having to take his parents to see a musical, and chide his mother for calling him "Mikey" and leaving potatoes on his state-secret-habouring laptop. He also admits to Sherlock that losing him would break his heart, and we're shown him seeing an imperiled Sherlock as a frightened little boy.
Descended Creator: He's played by Mark Gatiss, who is the co-creator of the series and a writer.
Evil Mentor: Not truly evil per se, but "The Sign of Three" suggests that a lot of Sherlock's mannerisms and habits are due to Mycroft's influence, subconsciously grilling him to be less emotional and more detached, whilst pushing him to find the answers.
Mycroft: But you don't understand the pain of it... the horror!
Formerly Fat: Gatiss claims Mycroft was on a lot of yo-yo diets.
In "The Sign of Three", Sherlock phones him to find him out of breath, commenting that either he's caught him in a compromising position or he's been working out trying to lose weight.
Genre Savvy: When John asks why Mycroft doesn't trust his own subordinates, Mycroft points out that they all spy on people for money. Which is ironic since he wanted Watson to spy on Sherlock for money.
Heroic BSOD: Has had two so far. The first is when Moriarty texts him to inform him his counter-terrorist enterprise has been compromised. The second is after Sherlock shoots Magnussen.
I Am the Noun: Like his Doyle counterpart. Actually, he one-ups him in a few departments:
"He is the British government — when he's not too busy being the British secret service or the CIA on a freelance basis."
Ice Queen: A true male example - Moriarty's code name for him is "The Iceman". Mycroft's feelings only extend to Sherlock's well-being; everyone else is expendable.
Mycroft seems to only let himself feel any sort of attachment, however remote, to Sherlock and his immediately family. He even worries that Sherlock developing feelings for his small group of friends will leave him vulnerable. Mycroft even goes so far as to remind Sherlock of his childhood pet having to be put down to warn him about the dangers of emotions, a lesson he himself has learned and mastered.
Not to mention that Sherlock's "queen" joke [see Ambiguously Gay above] combines with this to form a rather interesting pun.
Instant Expert: He claims he learned Serbian in two hours. Sherlock mentions he's slipping, to which Mycroft replies it's because he's reached middle age.
Intelligence Equals Isolation: Unlike Sherlock who has John, Molly, Greg, and Mrs. Hudson as his friends, Mycroft has nobody except his brother, and that's rocky most of the time.
Reinforced in "The Empty Hearse" by none other than Sherlock, who wonders what Mycroft did for two years without him and eventually forces Mycroft to say, "I'm not lonely, Sherlock."
In the same conversation, he comments that since he is smarter than Sherlock, he's a little envious since - while his brother lives in a world surrounded by idiots - Mycroft lives in a world surrounded by goldfish.
Just the First Citizen: According to the world he "Occupies a minor position in the British Goverment" but is actually (according to Magnussen) the most powerful man in Great Brittain.
Kick the Dog: Sherlock doesn't like it when people insult Mrs. Hudson, remember? Mycroft telling her to "shut up" wasn't the wisest idea. Also mentioning Redbeard to Sherlock.
Ultimatley played straight becuase Moriarty, Irene, and Magnussen all know that the best way to get to Mycroft is through his brother.
He also loves his parents.
Man Child: Not as much as Sherlock. But it's still there, being around his parents brings it out in him.
My God, What Have I Done?: Subverted: it turns out he and Sherlock planned the fall and he deliberately leaked info about Sherlock to Moriarty.
OOC Is Serious Business: Magnussen has sensitive personal information on every important person in the Western World (and proably beyond that). He's seen blackmailing an MP and it's implied he's even blackmailing the Prime Minister. You'd think he'd want Magnussen out of the picture since he's a threat to British Security. But he does not want Sherlock to go after him in anyway at all, telling Sherlock "you go against Magnussen and you go against me."
He even tells Anderson and his friend to forget that Sherlock even mentioned Magnussen or else he'll throw them both in jail. He even tries to threaten John (it doesn't work).
Parental Substitute: Besides his "constant" worrying about Sherlock, it's made fairly clear in "Scandal" that Sherlock regards him as this:
Mycroft: (pouring tea) I'll be "mother".
Sherlock: And there's a whole childhood in a nutshell.
In "His Last Vow", after Sherlock kills Magnussen, Mycroft sees his brother as a scared little boy.
Pet the Dog: Regardless of how they interact, he does genuinely care for Sherlock, and respects Watson.
Ungrateful Bastard: In "His Last Vow". Sherlock has killed Magnussen. Instead of pardoning Sherlock, or hushing the whole thing up, he sends him on suicide mission for MI6. The MP who hired Sherlock to bring down Magnussen, Lady Smallwood is the one who signs the order. They only change their minds when Moriarty comes back, and realize how much they need Sherlock.
Unwitting Pawn: He gave Sherlock's life story to Moriarty (who he knows is dangerously obsessed with his brother) in exchange for something that, it turns out, never existed in the first place. Whoops.
Averted. If Sherlock is to be believed, it was Moriarty and not Mycroft or Sherlock who was the Unwitting Pawn all along.
Blue Blood: She's an MP who presumably sits in the House of Lords.
The Chains of Commanding: She's not particurarly thrilled to sign the order for Sherlock's exile, but does so anyway in the interests of "justice."
Genre Savvy: When Magnussen threatens her with blackmail of her husband to stop a government investigation against him, her solution is to go to Sherlock.
Iron Lady: Absolutely refuses to let Magnussen walk over her or her husband.
MI6: It's implied one of her duties as an MP is to look oversee British Intelligence, meaning she is technically Mycroft's superior.
The Stoic: Keeps her cool, during her episode with Magnussen.
Ungrateful Bitch: Signs an order for Sherlock to be sent on suicide mission for MI6, after he kills Magnussen, on Mycroft's behest. Although she notes it is "hardly merciful".
Unwitting Instigator of Doom: Asking Sherlock to bring down Magnussen sets off a chain of events that lead to Magnussen being murdered by Sherlock, and nearly exiled stopped only by Moriarty's "resurrection".
Mike: I heard you were abroad, getting shot somewhere what happened?
John: I got shot.
Nice Guy: He's doens't seem particularly annoyed by Sherlock unlike most people. He also offers suggestions to John on how to find better living quaters in London.
Put on a Bus: Hasn't been seen since A Study in Pink, although he's a frequent commentator on the blogs, a Sherlock Scan in A Scandal in Belgravia reveals John spent a night out with him, and he sends a telegram to John's wedding apologizing he couldn't make it.
Shipper on Deck: In a platonic sense. He's the one who introduces John to Sherlock, and he's smirking the whole time while Sherlock rattles off his deductions about John.
Molly Hooper (Louise Brealey)
"I know what that means, looking sad when you think no-one can see you."
All Love Is Unrequited: Is hopelessly in love with Sherlock. In The Empty Hearse she claims to be over him and has a fiancé, but her fiancé turns out to look a lot like Sherlock even to the point of dressing like him. In The Sign of Three she spends most of the wedding looking at Sherlock instead of her boyfriend or John and Mary. The engagement has ended by His Last Vow a month later.
Anger Born of Worry: Actually slaps Sherlock three times for failing a drug test, then chews him out how he could be so careless and to apologize to his friends.
Armor-Piercing Slap: Gives Sherlock a doozy when she finds out he's fallen off the wagon. John asks her if Sherlock's clean, Molly merely walks in front of Sherlock, braces herself, and wham... wham... wham!
Ascended Extra: Originally a minor character in Series One, she became a major character in the following series.
Beneath Suspicion: It turns out that Sherlock asked her to help him fake his death, knowing that Moriarty wouldn't be keeping an eye or bothering to target her, since he'd dismiss her as being not important enough for Sherlock to care about.
OMG! I nearly just wrote 'At least Toby will never leave me'. I am becoming a Mad Spinster!
The Cutie: Easily the nicest character on the show. And just look at her - she's so cute!
Dogged Nice Girl: To Sherlock. No matter how horribly he treats her, she just can't give up on him.
Grew a Spine: She's noticeably more assured and less awkward in Series Three, refusing to put up with Sherlock's more mean-spirited antics.
Ignored Enamored Underling: To Sherlock, who only returns her affections when he wants something, at least in the first season. Although he doesn't return her romantic feelings, he does see her as a friend.
Replacement Goldfish / Selective Obliviousness: Despite her belief that she's moved on from her unrequited crush on Sherlock, she's completely oblivious to the fact that her new fiance Tom looks and dresses exactly like him. No one has the heart to tell her.
Averted in "The Empty Hearse", when Sherlock brings her along on the case. Molly thinks she is there to replace John but Sherlock is trying to thank her.
Sarcasm Mode: Actually capable when pushed: her response to John asking if Sherlock is "clean" of drug use is to vocalize a very bitter-yet-subtle "Clean?".
Secret Keeper: Moriarty's failure to recognize her as among the people Sherlock cares about lead to her being one of the only people to know he isn't dead.
Throw the Dog a Bone: Her relationship with Tom in Series 3, who aside from being the spitting image of Sherlock is her first love interest who's not a sociopath. And as she cheerfully comments, she's now getting regular sex.
Sadly it's ended by "His Last Vow", a month later. It might have been because she stabbed him in the hand with a plastic fork.
As You Know: Her screen-name is "Marie Turner" which is her friend's name (Mrs. Turner, next door, with "the married ones"). Becomes a Running Gag on Sherlock's site and John's blog where every time she comments, she immediately double-posts a reminder: "It's Mrs. Hudson, by the way."
With the exception of the one time Mrs Turner herself actually commented.
Berserk Button: Harming her is officially Sherlock's, considering he throws her attacker out a window multiple times.
Being rude to her is another, even stunning Mycroft with how angry he got when Mycroft told her to shut up in irritation.
Don't lead her on, or let her find out about your marriage from Sherlock.
Brainless Beauty: Anyone who unknowingly marries a major drug kingpin can't be much in the way of a detective.
Catch Phrase: "I'm your landlady, dear, not your housekeeper!"
Cloud Cuckoolander: She's cheerfully oblivious to most of Sherlock's strange living habits. Or she simply doesn't care. Or, given hints in Series 3, she's quite often stoned. That said, she does have a bone to pick with a few of his habits. Upon finding that Sherlock keeps thumbs in the fridge, she reacts with disgust, and she also seems extremely panicked by him shooting holes in the wall- though her reaction to this is just to scold him like a child and add repair costs to his rent.
Mrs. Hudson: I'm putting this on your rent, young man!
Cool Old Lady: Mrs. Hudson is one of a select few who can tolerate Sherlock for extended periods of time, gave Sherlock a special deal on the apartment (as thanks for helping her out with getting her husband executed), and keeps some kind of "herbal soother" in her apartment that she doesn't want the cops to know about.
She also pretends to be much more of a fragile old woman than she actually is when captured by the Americans in order to hide the fact that she has the phone they're looking for. When Sherlock throws the guy out the window, her first reaction is simply that her bins are getting dented.
Dark and Troubled Past: Series 3 later reveals that she's a former exotic dancer, and that whilst she lived in Florida, unbeknownst to her, her husband had gotten involved in and eventually ended up running a local drug cartel, before being eventually caught and executed for double homicide. She actually found this something of a relief and even formed a friendship with the man responsible for securing his conviction, Sherlock. Although she was perhaps more involved than she'd like us to know:
Sherlock: Even your landlady used to run a drugs cartel
Mrs Hudson: It was my husband's cartel, I was just typing.
G-Rated Drug: Her "herbal soothers" she doesn't want the drugs bust to find.
Fridge Brilliance comes into play after the revelation in Series 3 that her husband was involved in running an American drug cartel, since being found in possession of illegal drugs could cast doubt on her being unaware of his activities, causing her to risk accusations of perjury and even extradition by the American authorities.
Avert in "His Last Vow", when Magnussen's scan of her reveals outright she uses marijuana.
Informed Deformity: Her notorious hip has come up multiple times, and yet, she's never seen limping or otherwise uncomfortable because of it, and she seems to have no trouble going up and down the stairs in 221B.
Never Mess with Granny: Played CIA agents, police officers, and even Watson himself in "Scandal" by faking tears and sneaking Irene's phone out in her bra.
Odd Friendship: With Sherlock, the man responsible for getting her husband executed in America.
Parental Substitute: Dotes on Sherlock and John like they were her own grandchildren, she even brings Sherlock his morning tea.
She's one of the few people Sherlock is openingly affectionate to her, and doesnot take it well if she's threatened.
Screaming Woman: Twice in Series 3. The first one is played for laughs when Sherlock reveals himself after pretending to be dead. The second time is not played for laughs is when Moriaty comes back from the dead, and Mrs. Hudson is understandly freaked out by the prospect.
Shipper on Deck: Mrs. Hudson might be pushing eighty, but she's a great, gushing fangirl at heart. She initially assumes that John and Sherlock are a couple, and wouldn't be persuaded otherwise. However, after Season One (especially during the events of "A Scandal in Belgravia") it appears that she doesn't think of them in that way anymore. Or perhaps she's just keeping that to herself now.
In "The Empty Hearse", she's shocked that John is getting married to a woman, especially so soon after Sherlock. John responds once again insisting that he's not gay and that Sherlock was not his boyfriend.
Shrine to the Fallen: Left Sherlock and John's flat exactly as it was during the two years Sherlock was "dead", admitting she didn't have the heart to move anything or even dust, since Sherlock always refused to let her clean the flat.
Shadow Archetype: To Molly. Molly is a Dogged Nice Girl, Kitty is a Stalker with a Crush. And both of them prove to be rather important in "The Reichenbach Fall", as Moriarty sold his "story" to Kitty after Sherlock tore her down, helping to spread the belief that Sherlock is a fraud. Molly, meanwhile, despite being treated badly by Sherlock, still seems to step up to help him behind the scenes of "Reichenbach". Also, they both display admirable loyalty to Sherlock and Moriarty, respectively.
Smug Snake: She reeks of desperation and uses every tactic in the book to wring a story out of Sherlock. It doesn't work, as he finds her repellent.
Wrong Genre Savvy: Clearly thinks she's an Intrepid Reporter who has uncovered the truth that Sherlock is a fraud and responsible for the crimes he's solved, while Moriarty is merely an actor suffering a crisis of conscience. Alas, no.
Mary Morstan/Watson / A.G.R.A. (Amanda Abbington)
Admiring the Abomination: While most of John's past girlfriends are mentioned to have absolutely hated Sherlock due to his various personality quirks and mildly sociopathic tendencies, her reaction to meeting him is to grin and admit;
Fangirl: Certainly reads John and Sherlock's blog like one. And she pushes them to investigate the Bloody Guardsman case together even though they're both trying to be "responsible" so as not to upset the fragile three-way balance.
Kindhearted Cat Lover: One of Sherlock's deductions is that she is a cat lover, and she certainly fits the kindhearted part of the trope.
Manic Pixie Dream Girl: Aversion. While she helped pull John out of his depression after Sherlock's disappearance, there's more to her than that. She's the only one of John's partners who has understood the importance of his relationship with Sherlock without becoming jealous because of it.
Nice Girl: She's a genuinely compassionate person but also no pushover. When informed by Sherlock that one of John's cousins secretly hates her, Mary smiles serenely and moves the cousin's seat at the reception from the main table to next to the bathroom.
One True Threesome: Invoked. Mary seems fine with John's non-sexual bromance with Sherlock in addition to his romantic and sexual relationship with her. Sherlock actually seems to enjoy her company, actively accommodating her wishes instead of simply tolerating her presence. The three of them get along astounding well in "The Empty Hearse" and "The Sign of Three", with the closest he comes to displaying any sort of irritation towards her being when she tagged along to prevent Major Sholto's death, which in fairness occurred at her wedding. Their fragile equilibrium only seems to become unbalanced when Sherlock realises that she's pregnant.
In "His Last Vow", their dynamic shatters when it's revealed she used to be a professional assassin for the CIA. After some initial shock (and a bullet wound) Sherlock doesn't seem particularly bothered by her former occupation, being more upset she lied to John than anything else. John on the other hand is understandably furious.
Only Sane Woman: The wedding planning scene, where she can see that both John and Sherlock are itching to go on a case together to reaffirm that they'll stay friends after the wedding, but she has to manipulate them both shamelessly to make it happen.
Foreign People Are Sexy: She's Irish and gorgeous, to the point Sherlock specifically notes her beauty in his wedding toast.
Nice Girl: From what we see of her she's very pleasant and outgoing.
The Pawn: A particularly unlucky example. Not only did Sherlock pretend to fall for her to use her to get access to Magnussen, it turns out Mary independently cultivated a close friendship with her for the same reason. Mercifully Janine never found out about that aspect.
Punch Clock Villain: Only 'villainous' at all in the fact that she works for Magnussen as his PA; there is no indication that she is involved in anything unethical herself or knows the extent of Magnussen's criminality. Magnussen himself mentions he enjoys jabbing her the eye, the implication being that she only worked with him because he had found one of her pressure points.
Sexy Secretary: To Magnussen, though technically she is a PA. She hates him and only sticks around because of blackmail. It's implied he took sadistic pleasure in abusing her.
Vitriolic Best Buds: With Sherlock, in "His Last Vow" after she finds out she used him to get to Magnussen.
What the Hell, Hero?: To Sherlock, in "His Last Vow" after finding out how he used her. She tells him, clearly more hurt than angry, that he needn't have manipulated her and if he'd just trusted her they could have been friends.
Woman Scorned: Downplayed. While she does sell increasingly outrageous stories to the papers out of anger at Sherlock (and messes around with his morphine drip), she clearly doesn't hold a major grudge and even kisses him on the forehead before leaving. Sherlock conversely acknowledges he deserves it and congratulates her on at least making some cash for her troubles.
Mr. and Mrs. Holmes
Mr. and Mrs. Holmes (Timothy Carlton and Wanda Ventham)
Casting Gag: They are played by Benedict Cumberbatch's real parents.
Family Versus Career: Mrs. Holmes was a career mathematician, even having a published textbook. But she gave it all up for her children.
Happily Married: To the extent that Sherlock brings the Watsons down to their house when they have a bit of marriage trouble.
Good Parents: They certainly seem to be. They love their sons despite their....quirks, and take no notice when Sherlock steps onto the couch between them while they are telling him a story and pushes them out the door when John arrives.
In the Blood: Mrs. Holmes was a mathematician, so it's obvious Mycroft and Sherlock got their intelligence from her.
Iron Lady: Mrs. Holmes definitely gives off this vibe, even Mycroft is afraid of upsetting her.
Jerk with a Heart of Gold: Like her sons, Mrs. Holmes seems a bit cool on the exterior, but is a caring mother, going as far as to do Christmas dinner for the whole family, plus the Watsons, as Sherlock is suffering from a bullet wound and she wants to make sure he's okay.
Last Name Basis: Mrs. Holmes math textbook gave her the initials "M.L.," but that's about it, we don't really get a first name for either of them.
Mama Bear: "Somebody's put a bullet in my boy and if I ever find out who, I shall turn absolutely monstrous."
Nice Guy: Mr. Holmes is very pleasant and outgoing. He's even concerned about the Watsons marriage.
Odd Couple: Mrs. Holmes was a mathematician, Mr. Holmes is by his own admission a "complete moron."
Opposites Attract: From what we see of them. Mrs. Holmes is a bit temperamental, stubborn, and headstrong, whereas Mr. Holmes is much more laid-back, calm and passive. Many have noted they seem very similar to a time-shifted, partially-gender-flipped Sherlock and John.
Baker Street Regular: He's a drug addict Sherlock befriends while undercover in a crackhouse. Sherlock then uses him to communicate with Mary.
Composite Character: His first name, Billy comes from the page boy of 221B who first appeared in William Gillette's play, and than migrated into the stories as a relatively minor character. His last name Wiggins, comes from the leader of the Baker Street Irregulars in Conan Doyle's first two novels, "A Study in Scarlet" and "The Sign of Four".
Crouching Moron, Hidden Badass / Hidden Depths: Inverted; he's more Crouching Wimp, Hidden Genius - which is why Sherlock takes a shine to him. He's also apparently an excellent chemist, capable of creating non-lethal drugs to knock out people without damaging their bodies.
Erudite Stoner: He might be a heroin addict but he also has deductive skills similar to Sherlock's.
Knife Nut: Pulls a knife on John during their first meeting and gets a sprained wrist in return.
They Call Me Mister Tibbs: Tried to pull it off by claiming to have a codename amongst the druggies as "The Wig." Sherlock doesn't buy it.