The courtroom scenes (filmed in St. Cloud, Minnesota) were "dressed up" to give it a more "hockey feel" this included adding small black circles that looked like hockey pucks near the ceiling architecture. Instead of taking them down, the "hockey pucks" still remain today.
Adam Banks is often referred to as a "Cake Eater." This term is actually well known throughout Minnesota and refers to people who live in the city of Edina, a suburb of Minneapolis. It refers to Marie Antoinette's infamous, "Let them eat cake".
Gordon takes the Ducks to see an NHL game between two teams that were both relocated a few years after the movie was released. The Minnesota NorthStars became the Dallas Stars in 1993, and the Hartford Whalers became the Carolina Hurricanes in 1997. Also, both teams have won the Stanley Cup since their moves: Dallas in 1999, Carolina in 2006.
The scene amid the ice sculptures was filmed during the St Paul Winter Carnival, in Rice Park where the ice sculpture contest occurs. It was originally planned for the ice palace that had been built by the Mississippi for the carnival, but an unseasonably warm January was melting the palace, making it unsafe to film inside.
Gordon takes the Ducks to see an NHL game between two teams that were both relocated a few years after the movie was released. In 1993, a year after the movie, the Minnesota North Stars moved to Texas and became the Dallas Stars, and The Hartford Whalers became the Carolina Hurricanes in 1997. Also, both teams have won the Stanley Cup since their moves: Dallas in 1999, Carolina in 2006. The team also watches the North Stars game at the Met Center in Bloomington, Minnesota. The Met Center was demolished two years after the movie, in 1994. (The site is now home to an Ikea store. Ikea is in the parking lot of the old Met Center site, but Mall of America is not on the former hockey arena's site at all. It's across the street on the site of the old Met Stadium baseball/football stadium former home to the Twins and Vikings.)
The original premise of Mighty Ducks was much darker with very little comedy about an ex-NHL player turned alcoholic who seeks revenge on his old coach by coaching opposite him. The main idea stayed when Disney bought the rights to the movie, but some elements were changed (such as Bombay is now a lawyer, who never played in the NHL, who must do community service for a DUI), including much more emphasis on comedy and downplaying most of the adult themes.
The only film in the trilogy where no one on the Ducks team is even referred to as the team captain. Banks is (mistakenly) referred to as captain in the second film, until Charlie later is. And Charlie is correctly called the team captain in the third film. (Before being stripped of it and then later, being awarded it again.)
The trivia items below may give away important plot points.
In the United Kingdom, the film is called "Champions" and in the British theatrical release, the song "We Will Rock You" by Queen plays at the beginning of the end credits instead of "Winning It All" by The Outfit, when Gordon gets on the bus. That same release plays Queen's "We Are the Champions" as the ducks celebrate winning the state pee-wee championship following Charlie's climactic penalty shot instead of the movie score.