* ActorAllusion: After scamming Seabass to pay for their bill, Lloyd says he saw it on a movie. The movie he is speaking of is ''Film/SomethingWild'' and Creator/JeffDaniels does the same thing to Creator/RayLiotta.
* BreakthroughHit: For The Farrelly Brothers.
* CaliforniaDoubling:
** Harry and Lloyd are supposed to be in Aspen, Colorado in the second half of the movie. Except the town they are in is actually Breckenridge. You can tell because Breckenridge has one main street where shops and restaurants are located with cross streets descending the hills on the east and west sides of the valley feeding into the main drag. Aspen is a town spread out across many blocks with rather busy traffic. Although both have ski resorts on one side of the town.
** In the scene where Harry and Lloyd are on the bed in the presidential suite, crying and blowing their noses with money, they are watching a commercial for Pacific Bell. If they are in a hotel in Aspen, CO there is no way they would have seen that commercial on a hotel TV when the ad is clearly for a company that serves the west coast. (U S WEST, now [=CenturyLink=], was the Baby Bell in Colorado.)
** The skiing scenes were clearly shot at Copper Mountain, not at an Aspen ski area. You can tell because the lift operators obviously wear Copper Mountain uniforms, not Aspen uniforms. Copper Mountain is over two hours drive from Aspen.
** The airport scenes in Rhode Island were filmed at Salt Lake City International Airport. In addition, Park City, Utah, doubles as Aspen during a few scenes set in town. Lloyd and Harry's apartment building is located in Salt Lake City, as is the building where Lloyd picks up Mary to drive her to the Airport. Finally, the building in Lloyd's Dream Sequence where he gives Mary her briefcase (and takes a peek at her rear) is La Caille, a gourmet restaurant and winery located just outside of Salt Lake City.
* DyeingForYourArt: Lloyd's chipped tooth is real - Creator/JimCarrey had chipped his years previously, and had it uncapped for this film.
** Creator/JeffDaniels also got his hair naturally frizzy that way by not conditioning, blow drying, or combing his hair for two months.
* MissingTrailerScene: Two of them:
** ''(when being pursued by the cops)'' "I have an idea. Go..... FASTER!!!"
** An alternate take of the "It's okay! I'm a limo driver!" scene, with Lloyd still moving as he says it.
* OneSteveLimit: Averted out-of-universe; actress Karen Duffy oddly played two characters named Shay that year, in this film and ''Film/BlankCheck''.
** Averted also with Creator/JeffDaniels, who played two characters named Harry in 1994, the other being in ''Film/{{Speed}}.''
* PlayingAgainstType: Creator/JeffDaniels was not a comedic actor before he made this film, but the Farrelly Brothers convinced the studio to let them have Daniels in their movie when they watched ''Film/SomethingWild".
* RomanceOnTheSet: Creator/JimCarrey and Lauren Holly married after meeting on this film, but it lasted less than a year.
* SequelGap: ''Dumb and Dumber To'' comes out 20 years later. The setting apparently has Lloyd spending all this time faking insanity to the point of catatonia just to prank Harry.
* StarDerailingRole: Averted, thankfully. Jeff Daniels was warned by his numerous people that if he took the part, his career was over. Never happened.
* ThrowItIn: Creator/JimCarrey threw in quite a bit, like "We landed on the moon!" and even "the most annoying sound in the world" (with the latter, you can clearly see Creator/JeffDaniels and Mike Starr trying to hold it together, bracing for whatever Carrey was about to do; [[{{Corpsing}} Daniels fails and loses his shit]] right before it cuts to a close-up of Starr).
** Also, "Big Gulps, huh? Well, see ya later!"
* WhatCouldHaveBeen:
** Creator/NicolasCage and Creator/GaryOldman were the original choices to play Harry and Lloyd.
** Creator/SteveMartin and Martin Short both turned down the role of Lloyd.
** Creator/RobLowe and Chris Elliott both turned down the role of Harry.
** [[spoiler:An entire subplot was filmed involving Mary's kidnapped husband Bobby being kept in a wooden shipping crate, but was ultimately discarded. The brief scene where Nicholas and Shay discuss the snow owl incident had originally led into a scene where Bobby manages to escape while still inside the crate]].
** An early draft of the film had Creator/MelGibson as Mary's husband, playing himself in a cameo role. This was going to be a gag because at the time, Mel Gibson was one of Hollywood's biggest heartthrobs, and somebody like Lloyd Christmas couldn't possibly hope to compete with him.
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