As an actor, writer and director, his body of work included some of the all-time great comedies.
His signature acting roles straddled the brainy and the hilarious, but even behind the camera Harold Ramis built a career in Hollywood on making people laugh and think at the same time.
The body of work left by the Chicago-born filmmaker, who died early Monday at 69 from complications of autoimmune inflammatory vasculitis, is full of some of the greatest cult and mainstream comedies ever.
"Harold was a force of good in the universe — so funny, sweet and thoughtful," said Jack Black, who starred in Ramis' final feature as a director, 2009's biblical send-up, Year One. "He will be deeply missed."
A one-time joke editor for Playboy magazine, Ramis joined Chicago's Second City improvisational comedy troupe in 1969 before moving to New York City for the off-broadway The National Lampoon Show, where he worked with fellow Second City alums and future Saturday Night Live stars John Belushi, Bill Murray and Gilda Radner. In 1976, he was a performer and head writer for the Canadian comedy show SCTV before switching to the big screen.
He co-wrote Animal House (1978), which made a movie star out of Belushi and influenced decades of college-set films. That kicked off a winning streak of screenplays starring his longtime collaborator — and fellow Windy City icon — Murray, including the 1979 camp comedy Meatballs, 1980'sCaddyshack (which acted as Ramis' directorial debut), the 1981 military spoof Stripes, and Ghostbusters from 1984.
"He earned his keep on this planet. God bless him," Murray said in a statement released to Time magazine.
Chevy Chase, whom Ramis directed in Caddyshack and the original National Lampoon's Vacation (1983), said in a statement he was "shocked and heartbroken" by the loss.
The actor added that it was Ramis "who acted out and gave me the inspiration" for his Vacation character, Clark Griswold. "I was really copying Harold's impression of Clark. He was a truly funny and highly intelligent man with great honesty and a great appreciation for the best kind of comedy."
Ghostbusters and its 1989 sequel cast Ramis, Murray and Dan Aykroyd as paranormal investigators and gave Ramis his signature on-screen role as Dr. Egon Spengler, a scientist who wasn't afraid of no ghosts but was really into spores, molds and fungus.
In a statement, Aykroyd said he was "deeply saddened to hear of the passing of my brilliant, gifted, funny friend, co-writer/performer and teacher Harold Ramis. May he now get the answers he was always seeking."
In addition to Caddyshack, and Vacation, Ramis' directorial efforts included Groundhog Day (1993), Multiplicity (1996), Analyze This (1999) and its sequel Analyze That (2002), and The Ice Harvest (2005). Ramis won a BAFTA for best original screenplay for Groundhog Day, which starred Murray as a self-centered meteorologist who has to live the same day over and over until he gets it right.
Ramis had a small role as a neurologist in Groundhog Day, and usually his parts, major or minor, veered toward intelligence in the face of comedic high jinks. He was the likable voice of reason to Murray's anti-authoritarian Army recruit in Stripes, a doctor in As Good As It Gets and a wise father to a soon-to-be dad (Seth Rogen) in director Judd Apatow's Knocked Up (2007).
"Life doesn't care about your vision," Ramis says to Rogen in one key scene. "You just gotta roll with it."
"I looked up to him as a director but even more so as a man," Apatow said. "We hired him to play Seth's father in Knocked Up because we all saw him as the dream dad — funny, warm and wise."
Apatow said that Ramis was responsible for almost every movie that him want to be a comedy director, and the late director's films such as Animal House, Stripes, Ghostbusters, Vacation and Groundhog Day "are the touchstones of our lives."
He once interviewed Ramis when Apatow was 16 years old for his high school radio station, "and he could not have been more gracious and hilarious," Apatow added.
"Harold was one of the nicest people I have ever met, and he inspired countless people to go into comedy. His brilliant work will make people happy forever."
Contributing: Bryan Alexander