History Series / HappyDays

* ShooOutTheNewGuy: Pinky Tuscadero and the band's "black drummer" "Sticks" were both hyped in promos as new characters, but neither appeared for more than an arc before disappearing. Pinky's sister "Leather" was a stand-in for Pinky (whose actress apparently caused problems) but was again not common. Other examples include down-home hick cousin K.C. Cunningham (''Series/{{Wings}}'' Crystal Bernard) and Fonzie's temporary girlfriend and her [[Film/{{Poltergeist}} daughter]] for the second-to-last season.

The show started out as a nostalgic look at 1950s America, centered largely on [[ButtMonkey gee-whiz]] high school student Richie Cunningham (Creator/RonHoward) and his friends, family, and overall daily life in 1955 Milwaukee, Wisconsin. Said family included Richie's parents -- his father, hardware store owner and [[StandardFiftiesFather cardigan enthusiast]] Howard (Tom Bosley), and mother, housewife extraordinaire Marion (Marion Ross) -- plus his [[{{Tsundere}} sweet-and-sour]] little sister Joanie (Erin Moran) and, [[ChuckCunninghamSyndrome initially]], his basketball-playing slacker older brother Chuck (Gavan O'Herlihy[[note]]in season one[[/note]] and Randolph Roberts[[note]]in season two[[/note]]). But the show ended up becoming incredibly popular for [[BreakoutCharacter being the home of]] Arthur "Fonzie/The Fonz" Fonzarelli (Creator/HenryWinkler), initially a soft-spoken greaser side character who eventually became the Cunninghams' boarder, an auto mechanic, ''the'' ladies man, and more or less a descended god -- in short, the epitome of '50s cool.

** In "Fonzie For the Defense," Fonzie and Howard are called for jury duty. Fonzie is the only one who isn't willing to convict the African-American defendant. After Fonzie's knowledge of motorcycles proves the defendant could not have committed the crime, one juror remains unconvinced. Fonzie then becomes more direct with the Aesop.

** [[TropeNamer The original]]. After being played by two different actors, the second quitter led to Garry Marshall just axing Chuck entirely, and one day he ran up the stairs to his room and never returned; at the end of the GrandFinale, Howard makes a speech specifically mentioning that he and Marion only have two children. A very famous TV example, often subject to LampshadeHanging in other media about the show.

* ChuckCunninghamSyndrome: [[TropeNamer The original]]. After being played by three different actors, the third quitter led to Garry Marshall just axing Chuck entirely, and one day he ran up the stairs to his room and never returned; at the end of the GrandFinale, Howard makes a speech specifically mentioning that he and Marion only have two children. A very famous TV example, often subject to LampshadeHanging in other media about the show.

* ChuckCunninghamSyndrome: [[TropeNamer The original]]. After being played by three different actors, the third quitter led to Garry Marshall just axing Chuck entirely, and one day he ran up the stairs to his room and never returned; at the end of the GrandFinale, Howard makes a speech specifically mentioning that he and Marion only have two children, seemingly confirming that Chuck no longer exists. A very famous TV example, often subject to LampshadeHanging in other media about the show.

* ChuckCunninghamSyndrome: [[TropeNamer The original]]. After being played by three different actors, the third quitter led to Garry Marshall just axing Chuck entirely, and one day he ran up the stairs to his room and never returned. A very famous TV example, often subject to LampshadeHanging in other media about the show.

** In an outtake from the final show, after Mr C. toasts his family and friends one by one as written in the script, Tom Bosley breaks character to look around saying "[[ChuckCunninghamSyndrome Chuck! Where's Chuck?!?]]"

* LongRunnerCastTurnover: The only four actors who remained on the show throughout its entire run were Creator/HenryWinkler (Fonzie), Tom Bosley (Howard), Marion Ross (Marion) and Anson Williams (Potsie). Ron Howard and Don Most bost left the show to pursue other opportunities after Season 7. Erin Moran left during Season 10 with Scott Baio to star on ''Joanie Loves Chachi'', but returned for the final season. Several characters were put on the show to fill the presences left behind by several of the show's main actors. The cast had virtually been turned upside down by the end of the show's run, with so many different transitions and replacements for episodes, that you wouldn't be able to figure out that the original season's main cast members were only Ron Howard, Marion Ross, Anson Williams, and Tom Bosley.

* BreakoutCharacter: This trope used to be ''CALLED'' "The Fonzie", and Fonz remains the yardstick by which applicability of this trope to a character is measured. He went from an occasionally glimpsed greaser character to a centerpiece of the show thanks to his tough persona and catchprases, to finally the ''main'' character of the show. The network even wanted to rename the show ''Fonzie's Happy Days'' in the later seasons, and only didn't because Creator/HenryWinkler objected -- he felt (probably correctly) that Ron Howard was the real star.

* WeddingDay: Richie/Lori Beth in "R.C. and L.B. Forever", Arnold and a girl named Momo in "[[ExactlyWhatItSaysOnTheTin Arnold's Wedding]]", and Joanie/Chachi in "Passages (Part 2)".

** Fonzie: "EYYYYY!"

* ThisIsMySide: Ralph and Potsie play this totally straight in their apartment.

* ParentalFashionVeto: In the episode "The Fonz is Allergic to Girls" (the title MakesSenseInContext), Joanie Cunningham is going to a party with a towel wrapped around her but she's actually wearing clothes underneath it. Howard, her father, tells her not to go to the party like that but lets her go when she reveals that she's wearing clothes under the towel.

* ParentalSubstitute: Fonzie for Chachi.

** When Richie writes "I love you" by writing "I [heart]" and then drawing a sheep (as in "ewe"), everyone thinks he wrote "I love sheep". When he tries to explain to one guy, he asks, "How do you know it's a female sheep?".