Defictionalization: The NHL franchise. Though when they ditched the uniforms from D2 and the "Mighty" part, they became a respectable franchise and even won The Stanley Cup. Following a change in ownership.
Amusingly, given the theme of the movies, the cup-winning Ducks team in 2007 was known for being relentlessly physical. They led the league in fighting majors that season.
Ice Hockey events were part of the first ever Youth Olympic Games in 2012, as the Goodwill Games were essentially a lower-grade version of the Olympics after the Cold War ended.
Deleted Scenes: At least two in the first sequel. The first took place after Team USA follows Bombay on the golf cart roller blading. Portman and Fulton begin to bond, Coach Bombay and Ms. McKay get to know each other, and the scene ends with Fulton, Guy, and Jesse crashing the golf cart. The second involved the team members who didn't go to Rodeo Drive getting into a brawl with the Iceland team while hanging out at the beach.
Dyeing for Your Art: Elden Henson is a natural blonde, and dyed his hair black in all 3 films in order to play Fulton Reed alongside his real-life brother Garette as Guy.
Market-Based Title: In the UK, the first film was retitled Champions, which also became its name in a number of other countries in Europe and South America. D2 was, confusingly, retitled The Mighty Ducks in the same regions. The UK home video release for Champions tweaked the name to The Mighty Ducks are the Champions, perhaps in an attempt to better tie the two films together, but it only made it look like the first movie was the sequel to the second. With the trilogy being available for streaming when Disney+ launched in the UK in 2020, the film finally reverted to it’s original title.
Real-Life Relative: Elden Henson (Fulton) and Garette Ratliff Henson (Guy) are brothers. Elden had to dye his hair black and use a stage name (he's credited as Elden Ryan Ratliff) so he could play Fulton.
Role-Ending Misdemeanor: The child actor originally cast as Adam Banks (whose identity has never been revealed) was fired from the film after he cross checked Marguerite Moreau (Connie) in the back during a training session.
Steven Brill's original idea for a hockey movie was about a teen from Minnesota moving to Los Angeles and starting a team there.
The original script was much darker and adult themed. Once Disney picked it up, it was revised to tone down the overtly adult elements and add more comedic scenes revolving around the kids.
Charlie Sheen was offered for the role of Gordon Bombay, but turned it down and later on his brother, Emilio Estevez, took the role. Bill Murray was deemed too old for the role, while Chevy Chase, Tom Cruise, Michael J. Fox and Tom Hanks were candidates. Steven Brill, who wrote all three films, wanted to play Bombay and was turned down, he was given the role of prosecutor Frank Huddy as a consolation.
Jake Gyllenhaal was the first choice for Charlie, but his parents wouldn't let him move to Minneapolis for filming so the creators cast Joshua Jackson instead.
Actor Jack White appears in all three films, in two different roles. In the first two films, he was a referee. In D3, he played Coach Wilson, the Varsity team's head coach. White has been involved in many films where hockey was the main focus or part of the story, including this trilogy, mostly as what IMDb calls a "hockey technical advisor".
Scott Whyte played Gunner Stahl in D2 then came back for D3 as Scooter Holland.
Steven Brill plays a different role in each film.
In D3, the Varsity team are played by the same actors who played the Hawks in the first film.