A series of graphic novels by Jeff Kinney based off his webcomic of the same name, aimed at kids around the age of 12 years old. They tell the story of Greg Heffley, a self-proclaimed "wimpy kid" attempting to navigate the pitfalls and perils of middle school life. The books are presented as Greg's journals. Befitting a child's diary, they are filled with handwritten notes and stick drawings of his daily adventures.Greg's family includes his mother, Susan; his father, Frank, and his two brothers, Rodrick and Manny. Rodrick is older and often picks on Greg, whilst Manny is the baby of the family who can get away with anything. Other kids in the neighborhood include Greg's friend Rowley, and the creepy kid Fregley, who lives down the block.The books to date are:
There is also a Do-It-Yourself Book (2008; expanded in 2011) and, tying in with the film adaptation of the first book, a making-of Movie Diary (2010; updated in '11 and '12 to include the sequels).See also Zombie Kid Diaries, a parody of this series which the author actually sued the creators over.
Adaptation Expansion: Especially in the second movie. In the books, at Rodrick's Wild Teen Party, Greg is locked in the basement all night until Rodrick needs help cleaning up from it. In the movie, Rodrick locks Greg in the basement, only for him to find a phone down there and call Rowley to come rescue him. When his parents call, Greg threatens to tell their parents about the secret party if Rodrick doesn't let him out, so Rodrick lets him out. Also in the book, their parents don't find out until they go through the camera and see a picture accidentally taken of the party, in the movie however their mom finds out when a bathroom door they had to replace has no lock on it.
The movies also expand on the school that Greg goes to; it's called "Westmore Middle School" and has a hornet as its mascot.note The hornet mascot later made it into the 8th book.
Adults Are Useless: Most of the grownups in the books are idiots, to put it lightly. It's not only a genre trait of school-themed works, but also stories from the point of view of a teen. Greg's mom is arguably the most useful...but she's just out of touch.
In the books one of the comics submitted for the contest (And a few bonus ones in the Do-it-yourself Book) was called "Girls Rule" which the entire punchline is about extremely shallow girls insulting boys and other girls for their fashion. Obviously reflecting the traits of the girls who wrote it. Despite never being shown as actual characters, there is no denying they are Alpha Bitches.
Subverted to the point where it actually helps Rowley's image out in the film.
Ambiguous Disorder: Fregley seems to have something on the Autism spectrum, what with the supposedly being very smart but the complete lack of understanding of social norms and personal boundaries and his strange speech euphemisms (screaming "juice" when he needs to go to the bathroom, for example).
Sometimes, Rowley's actions are a bit suspect, especially with Greg. You'd think that a 12-year-old boy would realize that sharing a "Best Friends" locket (in the shape of a heart) with another 12-year-old boy would be weird or realize that being a fan of a rather effeminate pop singer isn't exactly manly. It could be argued that he's just completely unaware of these things considering that he is a Cloudcuckoolander and is completely sheltered, however. Also supporting this is that he's the one who gets a girlfriend in The Third Wheel.
Greg himself has his moments... a lot of moments. However, his frequent crushes on girls, not to mention the events of The Third Wheel, push him safely into Camp Straight territory.
In the movies, Fregley seems a little too willing to get close to Greg.
Dad: Well, for starters, Benjamin Franklin didn't fight in Vietnam...note In the book, it's changed to "For starters, Abraham Lincoln didn't write To Kill a Mockingbird."
Art Shift: In the movies, sometimes the perspective will change from live-action to animated versions of the book illustrations.
Artistic License - Biology: Greg stated in his science project that the moose, along with humans, evolved from birds. The teacher was not amused.
Ascended Extra: Diary of a Wimpy Kid itself. It used to be a very obscure webcomic on a site meant for elementary school-age kids. Now it's a wildly popular 8-book series with three movies and more books to come.
Asian and Nerdy: One girl in Rodrick's middle school, Kathy Nguyen, was voted onto the "Most Likely To Succeed" page in the school yearbook.
Big Screwed-Up Family: The Heffleys are definitely not a stable family. Frank's a Jerk Ass and Bumbling Dad, Susan's absolutely oblivious to how teenagers are nowadays, Rodrick's a step away from dropping out of school, Manny can't seem to stay in school and Greg is a slacker who could very well end up like Rodrick.
Bile Fascination: In-Universe - Greg and his dad can't resist reading the dreadful comic Li'l Cutie (a parody of The Family Circus) just to see how bad it is. (One of the captions for a Li'l Cutie comic was, "Daddy, is rain just God sweating?")
Bishōnen: Rowley's favorite singer, Joshie, is more or less described as being one of the sort. Emphasized in The Ugly Truth when Rowley goes to a Joshie concert and notices that he is the only boy in the audience.
Black Bead Eyes: All of the characters have these. Unless they're wearing glasses of course, but even with that Patty Farrell is an exception.
Black Sheep: Several members of the extended family — especially Uncle Gary who is explained as having been married at least four times. It gets worse in The Third Wheel when he moves in with Greg and company.
Blind Without 'Em: Patty Ferrell. Greg is also revealed to be one in the third book (he wears contact lenses).
Bread, Eggs, Milk, Squick: "I can name at least half a dozen jobs I can never have if I can't grow a beard or a mustache or at least dome decent stubble." The jobs Greg lists? Magician, pirate, lumberjack, artist, cop, and...criminal.
Brick Joke: There's a picture in The Last Straw that reveals that Greg once turned in a book report 4 pages long (cover included), and only a few sentences long because he took up more than half of the last page writing "THE END" in big letters, using the excuse that he was running out of paper.That spoiler-tagged part comes up at the end when Greg admits that he was ending his story on sort of a generic happy ending note, but he admits that he's running out of paper...
In "Hard Luck", the Easter egg hunt plot goes nowhere. However, near the end of the book, the egg is found in a pile of wood in Gramma's yard.
Also in Hard Luck, Fregly claims he can blow a bubble with bubble gum in his belly button. It doesn't work, and Greg comments that he should have known that was impossible. Later, Greg's taking his picture for the yearbook, and he does it, much to Greg's shock.
Butt Monkey/Iron Butt Monkey: Any boy in Greg's year that isn't popular (i.e. anybody who's not Bryce Anderson and his flunkies), it's just that we see Greg being a Butt Monkey the most since it is told from his point of view.
Character Development: Throughout the books, Rowley learns to stand up for himself and grow a spine instead of blindly following people. By the end of The Third Wheel, he's also learned how to talk and relate to girls via the student council, becoming a couple with Abigail.
Chekhov's Gift: In book 4, Greg gets a "Ladybug", a phone that can only call home and 911, for his birthday. At the end, he calls 911 with it because he thought Frank was going to sell him (It Makes Sense in Context).
Chekhov's Gag: The sheer number of gags and comic setpieces that turn out to be these goes up with each book. In Book 7, for instance, Corny's Family-Style Restaurant turns out to be where Greg goes with Abigail and Rowley for dinner before the dance.
Children Are a Waste: Greg says that when he grows up, he wants to spend his money on himself and not a bunch of ungrateful kids.
He also makes sure to dispose of his gum and Popsicle sticks properly out of fear of being clones when he's rich and famous, and said clones come to his house asking for money.
Chuck Cunningham Syndrome: Trista, a girl from New Mexico was introduced and set up to be a major character at the end of The Last Straw. After a brief appearance in Dog Days, she's never heard from again. Justified since she ditched Rowley and Greg at the country club in the summer between the end of The Last Straw and the beginning of Dog Days.
Subverted with Aunt Cakey — she made an early appearance in the webcomic, disappeared from it and never appeared in any of the other media...and then had a minor role in 2013's Hard Luck.
Cloudcuckoolander: Fregley is this to the point where he gives Osaka a run for her money in the weirdness department. Rowley is a less extreme example.
Clueless Chick Magnet: Rowley. He doesn't seem to be all that interested in girls, yet in Rodrick Rules he's managed to socialize with some of the most popular girls in his year. At the end of Book 7, he ends up in a relationship with Abigail. It doesn't last, but that he'd be used to make another boy jealous is impressive.
Cringe Comedy: From start to finish, each book is filled with it.
Cut and Paste Comic: The artwork in the illustrations is reused constantly. (Explains why there is a Christmas Tree in the background when Greg is opening his Wonderwoman Underoos Birthday present in July.)
Deadpan Snarker: Greg, but his dad isn't really far behind him in levels of snarkiness.
Death by Newbery Medal: Greg is aware of this trope. When his mom tries to organize a summer reading club in Dog Days and assigns him Charlotte's Web, he predicts that either the girl or the pig pictured on the cover won't live to the end of the book. He never learns he's wrong — it's Charlotte the spider who dies — because he only gets three chapters into it.
In the movie, Patty holds a massive grudge over Greg because he insulted her in kindergarten. And the movie deals with the characters entering middle school.
In the webcomic, Greg writes an allegory story for school involving a monkey attempting and failing to fix a car, then shows it to Rodrick, who's fixing his own car. When Rodrick gets it, he not only tears up Greg's story, he tells all his friends about Greg's embarrassing incident in the retirement home toilets.
Don't Touch It, You Idiot!: In an incident from the original webcomic that becomes a flashback in Hard Luck, a younger Greg has to stay with his Aunt Cakey for the night while his parents are on a trip or something. Right before Greg goes to bed, Aunt Cakey tells him not to touch the iron because it's still hot. Guess what Greg does after Aunt Cakey goes to sleep.
Downer Ending: The fourth book ends with Greg and Rowley's friendship temporarily in shambles and Greg's vacation being absolutely atrocious.
Duck!: Greg and his dad in this scene in Dog Days.
Greg:(Dad is standing up in the canoe and about to hit his head on a tree branch) Duck! Duck! Dad:(looking through binoculars) Where? Where?
Dumbass Has a Point: The very few times Rowley calls out Greg for being unfair, he's completely right.
Eye Scream: In the webcomic, Greg's pet angelfish has its eyes ripped out by Rodrick's fish. 
Embarrassing Old Photo: Used a lot actually. There is a time in which Rodrick had a high-school yearbook that had his second grade picture instead of his seventh, due to a screw up on the part of Greg's dad.
It's implied that that's actually his name, however, as Greg calls his mother "Mrs. Pants".
Exact Words: In Rodrick Rules, Rodrick drives Greg home, but makes him ride in the back. He then slams on the brakes each time that Greg hits his head. The next time Rodrick drives Greg, Greg asks him to please go easy on the brakes. What does Rodrick do? Say "okay", but then go over every speed bump he can.
The Faceless: A character in the webcomic named Herbie Meaner. He's the leader of a gang of bullies and the reason why no sane kid in Greg's school stays on the basketball courts past 3:00.
Flanderization: Rowley was simply gullible and slow on the uptake before becoming a kiddy kid. This Flanderization is countered by his Character Development, however; The Third Wheel even implies that he is maturing faster than Greg is.
The Fourth Wall Will Not Protect You: In-universe, the movie about the muddy hand. The last person who sees the hand is always the next victim. At the end of the movie, the hand crawls straight towards the screen, implying that Greg and Rowley are the next victims. This kept them nervous and paranoid for the rest of the book.
Freeze-Frame Bonus: Pause Rodrick Rules when Greg and Rowley are checking out their YouTube video, and you can see that while the video only got four views, it received 24,963 comments.
In the third movie, the news report near the end has a ticker filled with strange news items, such as "High school kid accidentally eats salad", and "New 'square' wheel fails to impress".
Gag Nose: Many background characters are drawn with one.
Gaslighting: In Cabin Fever, Greg believes Rodrick was doing this to him with the Santa Scout.
Generation Xerox: In The Ugly Truth, it turns out that Greg looks exactly like Frank's cousin, Terrence. He's not happy about it.
Genre Savvy: Greg knows that most classics his mom will force him to read will have the Death by Newbery Medal trope. He does mess up on one prediction, though. He says that because Charlotte's Web is a "Classic", either the girl or the pig won't make it to the end of the book. He doesn't finish it, so he doesn't realize that it's Charlotte the spider who dies.
Hood Ornament Hottie: Referenced. Manny gets ahold of one of Rodrick's magazines, which Greg mentions has a picture of a woman in a bikini spread out on the hood of a car on the cover. Manny brings it to show-and-tell Although Greg said it was "nothing to get worked up over", their mother is not pleased.
Horrible Camping Trip: In The Last Straw, the father-son Boy Scout trip is a wash for Greg and his dad after the first night. And it's not even Greg's fault!
Humiliation Conga: Greg suffers one at the beginning of the second movie, which finishes with him falling into a cake and subsequently getting beaten up by the irate birthday girl and her friends.
Hype Backlash: In-Universe in the webcomic; Gregory is shown as being incredibly anxious to play a video game called "Twisted Wizard 2" and then says it's the lamest game ever made (mainly because of a horrible control scheme).
Hypocritical Humor: Greg gets an honorable mention in a contest for anti-smoking posters. The person who won first prize smokes at least a pack of cigarettes a day.
I Do Not Like Green Eggs and Ham: When Rodrick tells Greg that Rowley's new babysitter Leland is the biggest nerd in high school, Greg is reluctant to play Dungeons & Dragonsnote in the books it's Magick and Monsters, likely due to copyright restrictions. Subverted in the fact that while Greg actually likes D&D, he agrees with Rodrick that Leland is a nerd.
Ignoring By Singing: In the third book, when Greg and Rowley are being driven to a roller skating rink to impress Holly Hills and Susan overhears the conversation:
Let's just say that Rodrick would drive anyone to commit fratricide. He ALWAYS abuses his brother for no good reason (and it goes way beyond the normal siblings-pick-on-one-another thing), and he never gets in trouble for it. He also has NEVER been nice to Greg ONCE in the book. Even when Greg does something really nice for him at the end of Rodrick Rules, he doesn't ease up, even for a bit.
Well, there was one time (I forgot which book) where Rodrick taught Greg how to cut corners when they have to rake the leaves in Grammy's yard. Greg even comments how unusual this is, and that it's what older brothers are "supposed" to do.
Greg's dad also is a pretty big one. He is very mean to his kids (although not to the extent of Abusive Parents) and has NEVER shown one bit of love to Greg, unless you count him not sending him to military school. That was only after Greg's wimpiness helped him.
Frank did go to scout meetings with Greg, and bought tickets to the baseball game so the two could bond. Sadly both events backfired horribly. He also bought Greg an expensive weights set for Christmas (that Greg then never used).
Aunt Cakey in the webcomic (and later the books). Even though it's Manny she's responding to, passing off his displays of affection as a sign that he needs speech therapy is pretty cold.
Greg himself. When he and Rowley often try to accomplish tasks together, he usually makes him do all of the work. Also, there's his treatment of Chirag Gupta and pelting Patty Farrell with apples. (The movie makes this a little more justified, by portraying Patty Farrell as an Alpha Bitch who is stuck on an insult he did in kindergarten.)
When Greg's mom wants Greg to no longer lie, he tells every single truth to the fact a 200 pound kid can't play basketball due to weight, to making his Mom stand in the rain to say she's not in the house in the second movie.
Karma Houdini: Rodrick. He NEVER gets punished for bullying Greg and not one bad thing has happened to him due to him doing said bullying. Manny as well as he is always screwing things up.
Greg himself once, in a flashback when he wrote very rude anonymous Valentine's Day cards to everyone in his class (case in point: "Dear James, you smell.") He was Genre Savvy enough to write a card for himself so the teacher wouldn't suspect him. It worked.
Manny no matter what he does. In Book 6, he shuts down all power in the house except for his room, steals food, water, toys and a space heater and leaves the rest of the family for dead during a blizzard. Despite all this, he receives absolutely no comeuppance whatsoever for his actions. Their mother only gives Manny a talking-to...in which he blames all his brattiness on no one teaching him how to tie his shoes.
Kiddie Kid: Greg's best friend Rowley acts like a seven-year-old. It's justified by the fact that he's extremely sheltered because of his overprotective parents.
Kids Are Cruel: Well, this is middle school, after all. Greg himself isn't above it; Chirag Gupta will tell you that firsthand.
Kids Shouldn't Watch Horror Films: In Dog Days, Greg and Rowley watch a B-Movie called Hello, You're Dead that they found in Rodrick's room, featuring a muddy hand. Rowley has his eyes covered the whole movie. Greg doesn't find the movie all that scary...until the end, when the "muddy hand" crawls straight to the screen, meaning the "hand" is coming for the viewer next.
Kiss of Life: Roderick gets one of these when he pretends to be drowning in order to attract Heather Hills, who's working as a lifeguard. Unfortunately, Heather ignores him, and he gets the Kiss of Life instead from a big burly guy who adminsters it on him despite Roderick being both conscious and obviously breathing
Memetic Mutation: In-Universe example: The local news channel captures Greg's mom dancing while taping Loded Diper's performance. After being uploaded to the internet, the video is dubbed "The Dancing Mom video".
Multiple Choice Form Letter: Greg does this in the first book, typing out his Christmas cards on the computer with parts missing so he could just fill in the necessary adjustments to it later. (It doesn't work completely well though, such as when he fills out a thank you card for a new pair of pants and he has to say that all his friends would be jealous of it or that he likes how it looks on his legs).
The candygram messages used to raise money for the Valentine's Day dance in Book 7 are designed for the giver to fill in their and the recipient's name. Greg tries to cover multiple bases by filling in the blank with one girl's name, then writing in a P.S. telling her that if she doesn't want to go to the dance with him, she should give it to a particular girl who sits nearby.
No Infantile Amnesia: Greg claims this applies to him at the beginning of The Third Wheel. He goes on to explain that he was born three weeks early because he couldn't take all the noise he heard from the outside world (especially because Mom was using prenatal speakers to talk to and play classical music for him) and that as a result he has been trying to catch up on all the sleep he missed out on ever since. His love of long baths also stems from memories of peacefully floating in the womb.
Noodle Incident: Throughout The Ugly Truth Greg and Rowley avoid each other following a massive fight at the end of last summer (which was never shown in Dog Days.)
Subverted in Rodrick Rules where Greg has often talked about how Rodrick is blackmailing him with an embarassing secret that isn't revealed until the end of the book. He got stuck in the woman's bathroom at the old folks home.
Mild example-in the webseries, Greg stays with a relative and complains over how boring it is. He then tells a story where him and Rodrick find an old board game at said relative's house. They open to find out that it was filled with spiders. Greg has a hard time opening boxes after that.
The Do-It-Yourself book alludes to this, with Greg saying to write your worst nightmares, and shows a drawing of Greg parachuting into a yard full of giant Tarantulas. Aside from these subtle references, this phobia is never brought up in the actual books.
A similar example comes up in the sixth book when Greg explains that he has a phobia of puzzles because when he opened a box of puzzles once, it was full of crickets.
Another in-universe example: In Dog Days, Greg watches an old B-Movie about a muddy hand who kills the person who sees it right after it kills someone else. The last shot of the movie implies that the hand will go after the viewer next, causing Greg throughout the rest of the book to try to prevent a muddy hand attack.
Yet another in-universe example occurs when a younger Greg gets scared because Shel Silverstein looks scary to him. His father uses this to his advantage by telling him if he gets out of bed he's run into the writer in the hall, who visits each day. Greg still doesn't leave his bed at night.
Played with when Greg has to draw what he thinks teenagers would draw after watching violent horror movies (as part of Rodrick's science project). Played straight when Manny accidentally watches one of the movies from the same project, then draws a bunch of pictures that scare Greg when he finds them. (It's never explicitly stated that the movie actually scared Manny; in fact, the picture in the book just shows him looking at the TV confused.)
Only Child Syndrome: Rowley. In the fourth book and in the webcomic, when Rowley has a nightmare, his parents rush to his aid and ignore that Greg was thrown on his face.
Parental Favoritism: Greg's parents clearly favor Manny, to the point where he's becoming a Spoiled Brat. Manny is allowed to get his way, such as throwing tantrums over minor things like how his sandwich wasn't cut the right way. And his parents let him do it.
Manny is also Gramma's favorite (all you need to do is look on her fridge for proof), to the point where everyone in the family (yes, even Susan) is aware of it.
Grandpa, however, will tell you straight up who his favorite is.
Periphery Demographic: An in-universe example: Rowley's favorite musician is a European singer named "Joshie", but Greg looks at the album cover and immediately tells Rowley that Joshie's music is more than likely targeted at eight-year old girls. More or less confirmed in the 5th book, when Rowley talks about the time when he went to a Joshie concert and is the only boy at the concert. (And the only one over 10, to boot.)
The Pirates Who Don't Do Anything: Zig-Zagged. Greg's mom doesn't appear to have a job, but he mentions that she runs an article in the newspaper, and it's implied she might have been a therapist (but one for younger kids if anything) but is implied to go to school. Otherwise...she's not really doing anything. Greg's dad escapes this because they don't mention what he does, only that he takes a carpool. This is arguably a case of Fridge Brilliance - it's told from Greg's point of view. What would he know about what his parents do on a day-by-day basis?
Actually the books outright state that his mother was at one point a Kindergarten Teacher.
Playing a Tree: Greg is a tree in his school's production of The Wizard of Oz. Subverted in that he wanted this role, in part because he didn't want to be in the show but was forced to audition by his mom. Another student ends up with the role of a shrub. He ends up delaying the start of the play due to stage fright. Greg even comments on how ridiculous the whole situation was. In the movie adaptation, Greg wanted a main role in the play to make Rowley jealous. He can sing extremely well, but he's a male soprano. The theatre director said the only soprano parts in the play were Dorothy (he quickly made her drop that idea) and the Trees.
Greg: You'd think that someone whose job it was to sit on the stage and do nothing could just suck it up for one performance.
Product Placement: A TV set in the first film plays Ice Age, another 20th Century Fox production. In the same movie Greg and Rowley are playing the Wii, as well as one of those books has an illustration and is subtly implied that Greg's mother is playing Wii Fit.
Bingo, for the old ladies that Greg's grandma hangs out with. They use things like lucky blotters and Bingo Trolls and whatnot when they play. ("One of Gramma's friends is so good she memorizes all her cards and she doesn't even NEED to use a blotter to mark them off.")
At one point, Greg accidentally calls out Bingo when he doesn't have the matching numbers and a rival table sends out one of their own to intimidate Greg because they don't like it when newbies win on their first night. Serious Business indeed.
Toilet paper for the students at Greg's school. One candidate for student council president didn't bother campaigning at all and his entire speech was him promising to make the school replace the regular toilet paper with the quilted kind. He won the election by a landslide.
It's decided that, since the school doesn't have enough money to replace the toilet paper, kids can bring in their own from home. The kids bring in so much of it, they have to carry bags of the stuff to class with them because it wouldn't fit in their lockers.
Shout-Out: To Tales of a Fourth Grade Nothing: in Dog Days, Greg and his family have a Father's Day brunch. Dad tells the story of his dog Nutty running away to a butterfly farm when he was a kid, and Grandpa reveals that Nutty didn't actually run away to a butterfly farm; he was accidentally run over by Grandpa's car. Angry, Dad leaves Grandpa with the brunch bill, goes out and buys a dog. Rodrick suggests that the dog's name be Turtle.
The Sherlock Sammy books are similar to Encyclopedia Brown. (In the webcomic, Greg really did use Encyclopedia Brown books for his book reports.)
Spoiled Brat: Manny. Though one could argue he's not to blame, the fact his parents are the ones who spoil him rotten and never tell him the difference between right and wrong, is practically child abuse.
Stupid Good: In-Universe, Greg's mom plays Dungeons & Dragons this way. For example, her solution to the party being attacked by a band of orcs is to give the orcs all of the players' food. She then gets the idea that the game is a good way to teach Greg and Rodrick to get along better.
Li'l Cutie. Oh, dear lord. "Daddy, is rain just God sweating?"
The Do-It-Yourself book features comic strips by some of the characters. Most of them fall under this. In Rowley's strip Action, the only action was one character hitting the other with a Frying Pan of Doom. The rest of the page is just them discussing what's about to happen.
Suck E. Cheese's: Corny's Family-Style Restaurant in Book 7. Greg has a traumatic experience trying to rescue Manny from the indoor playground, and the serving staff and overall chaos easily makes up for the lack of animatronic robots and video games. Remember, anyone who comes in wearing a tie clearly isn't having fun and will get it snipped off.
Symbol Swearing: Rodrick does this when he drops a glass on the floor and it breaks. Manny imitates him.
Sympathy for the Devil: Greg may not like his siblings very much, but he does feel sorry for them when they get the short end of the stick. He thinks Rodrick is grumpy because he's The Unfavorite in the family and he feels bad for Manny for being too afraid of other kids to make friends.
Precious Poochie could be a subtle Take That toward Peanuts. The two strips are not alike (Precious Poochie is shown sitting on a phonograph thinking "I just can't seem...to figger out...what's all the fuss...over these...new-fangled...phonograph devices!"), but both are being run in papers despite the author having died years ago. Whenever the newspaper tries to replace it with something fresh, the strip's elderly fans protest.
Sherlock Sammy is a Take That parody towards the Encyclopedia Brown series. It's described as they are all the same where some adult commits a small crime, makes some stupid mistake, and then Sherlock Sammy solves it and then makes the adult look like an idiot. ("Your first problem was that you forgot to convert Fahrenheit to Celsius!") In the webcomic, he actually names Encyclopedia Brown.
Title Drop: A partial one in the second movie when one of Rodrick's friends scribbles "Rodrick Rules" on the Heffleys' bathroom door.
This Loser Is You: The readers are meant to identify with Greg, who is not only a self-proclaimed "wimpy kid", but who regularly gets tormented from the bigger kids around him and hangs out with the likes of Rowley and Fregley.
TMI: Gregory makes a comic strip telling people not to talk about that sorta stuff in public.
Toilet Humor: Used a lot. For instance, Greg's secret in the second book.
Too Dumb to Live: After Greg and Rodrick buy fish from a pet store (an angelfish and a very aggressive, carnivorous fish, respectively), Rodrick never bothers to feed his fish or clean the bowl (it lives off the algae growing in the inside of the bowl). Greg's mom sees this and finds it to be gross, so she puts Rodrick's fish in Greg's fish's bowl. You can guess what happens from there.
Totally Radical: Parodied when Greg receives a book for Christmas called Math is Rad. "It'll help you get a jump-start on algebra!"
The It's Awesome to Be Mefilmstrip in the first movie.
The Swear Jar: Susan sets one up because Manny is learning too many bad words from Rodrick and Greg. And Manny gets the money.
The Un Favourite: Rodrick and Greg, Rodrick moreso than Greg (not by much though).
Unusual Euphemism: Greg and Rodrick have their own special language that allows them to swear at each other without getting in trouble (e.g. "Spooky stork!" "Squishy slime stick!" "Raspberry plastic tickle bear!").
Fregley's cries of "JUUUIIICE!" when he has to use the bathroom.
Web First: This series started a webcomic. Then it adapted into a successful book series, which in turn was made into a series of films.
Wild Teen Party: Rodrick throws one of these in Rodrick Rules when Frank and Susan leave. (When the parents take another weekend trip in The Ugly Truth, they have the boys' grandfather babysit all of them so this won't happen again.)
What Does She See in Him?: One's a snarky, Jerk Ass, grumpy, bumbling dad who hates teenagers, heavy metal, video games and only wants to toughen up his middle child while get rid of his eldest child. The other is a former kindergarten teacher who's a gentle, caring, well-meaning Moral Guardian mother who dances to heavy metal, loves her family for the way they are, the only thing wishing for them to be is more like a family and genuinely tries to do the best for her sons (though it's often lost because of her inability to understand the fact that problems teens face can't really be solved with methods used to solve problems for kindergarteners). They're married. Tropers, we present to you, Frank and Susan Heffley.
The "Holiday Bazzar" in Book 6 was never mentioned again after the signs were hung up.
Also in Book 6: Manny hacks Greg's Net Kritterz account and disables it, preventing Greg from being able to log in. It's never mentioned again after that, likely meaning Gregory's Little Friend died.
What You Are in the Dark: Greg lies and says he moved the Cheese in the first book (in the movie he says he ate it) to cover for Rowley being forced to eat it. Only he, Rowley, the teen bullies and (in the movie) Angie know the truth