At least twice during the movie we can see an octopus on a TV screen in the house. Of course an octopus has eight legs, and there are eight intertwined friends in the film (counting their friend Alex, who we barely see).
Lawrence Kasdan wrote the parts of Karen and Sarah specifically for JoBeth Williams and Glenn Close respectively, however both actresses initially wanted to play the role of Meg as both felt that they better related to that character over the ones chosen by Kasdan.
The characters were based on people Lawrence Kasdan lived with in the Eugene V. Debs co-op in Ann Arbor, MI, while attending the University of Michigan. Co-ops are co-ed housing in which the residents share household duties like cooking. This explains why the characters are so comfortable sharing the house and cooking, and are so attached to the Michigan football game.
The main house in the film is in Beaufort, SC. It is the same house where The Great Santini (1979) was shot. Director Lawrence Kasdan liked "The Great Santini" so much that he decided to shoot his film in the same house.
When Glenn Close walked in for the first reading, Tom Berenger did not recognize her. They had co-starred in a stage production of "The Rose Tattoo" in 1977, but, according to Berenger, she had lost 15-20 pounds, had a shorter hairstyle and thinner face, and he initially did not know her.
Lawrence Kasdan says the title, "The Big Chill is about a cooling process that takes place for every generation when they move from the outward-directed, more idealistic concerns of their youth to a kind of self-absorption, a self-interest which places their personal desires above those of the society or even an ideal."
For scenes in which Lawrence Kasdan anticipated using music, he would have the actors deliver their lines in voices much louder than normal. This was done so that when the songs were added to the soundtrack later in post-production the lines would be heard clearly above the music and sound natural.
Before actual shooting was to begin, Lawrence Kasdan wanted the cast to spend some significant time rehearsing together. As they travelled from California to Atlanta, Georgia and ultimately Beaufort, South Carolina, the actors had nearly three weeks of rehearsal time before the cameras rolled--something extremely rare for a film. JoBeth Williams believed it was partly due to the studio not wanting to spend a lot of money on the actual shooting process. More importantly, however, Kasdan wanted to give the cast and crew a chance to work out how they would play their scenes together and get to know each other well enough to achieve the effortless camaraderie that comes with the close long-time friendships depicted in the story. It was a strategy that all of the actors found extremely helpful in making their characters' relationships believable. "It's like playing on a wonderful team," said Kevin Kline at the time, "and it's fun being part of that team. It's a sharing, like sharing a victory when you've won. There's a beautiful exhilaration in team play, which is about as apt a parallel as I can make to this ensemble."
The first thing actually shot was a key flashback scene in Atlanta that Lawrence Kasdan always intended to be the ending of the film. It was a scene that showed all of the friends, including the deceased Alex, back during their college days making Thanksgiving dinner together. It was intended to depict how all of the friends were back then and finally show Alex as a contrast to everyone's different memories of him.
After filming the college Thanksgiving flashback scene, the cast and crew moved on to the picturesque town of Beaufort, SC and settled in for the remainder of the shoot. It was during the colder fall off-season for Beaufort, so the usual summer vacationers were absent, leaving a somewhat deserted feel to the area. With Hollywood so far away, and it being a time before cell phones or the Internet, contact with the outside world was limited, leaving the cast and crew to spend most of their time together off-camera as well, which helped in creating a tight communal atmosphere. When they weren't filming, the actors spent their time exploring the area, playing parlour games and having dinner together.
According to Mary Kay Place, Lawrence Kasdan would often time scenes so that they would move along at a certain clip. It was an effort to keep the scenes from running too long so that Kasdan wouldn't be forced to cut them down later--something he hated having to do.
Lawrence Kasdan didn't want all of the songs to necessarily be an obvious commentary on every scene, but rather something more subtle. He wanted it "in some oblique way to support the feeling of the movie."
When shooting was complete and the film moved into the post-production phase, editor Carol Littleton was faced with some challenges. Littleton, who had previously edited Body Heat (1981) and E.T. the Extra-Terrestrial (1982), found this to be a different kind of film. Not only did the vast majority of the action take place in one location, but the focus was on characters and dialogue rather than traditional story action. "It was really all about nuance and tone," said Littleton in a 2011 interview, "and constantly weighing the dramatic value. Looking for the small moments, the little remarks, that made the story."
Meg Kasdan, Jon Kasdan, Jake Kasdan:
Director Lawrence Kasdan's wife Meg plays the airline stewardess flirting with Sam Weber at the beginning of the film. Their son Jon plays Harold & Sarah's son in the bathtub, and their other son Jake plays the boy seeking Sam's autograph at the wake.
As he fights off the bat, Harold hums the theme from Raiders of the Lost Ark (1981), a movie written by Kasdan. Sam Weber's appearance, and career as a television actor, resemble Tom Selleck, who had to turn down the role of Indiana Jones in "Raiders" due to his commitment to Magnum, P.I. (1980).