On March 15th, 1977, ABC aired the first episode of Three's Company, a farce based on a British comedy series Man About the House. The show had a light premise that no one had much confidence in, but it set the record for the highest rated midseason replacment show of all time. It was a huge hit, surviving for eight seasons through multiple cast changes and behind-the-scenes drama, and produced two spin-offs.
In this pilot episode, florist Janet Wood (Joyce DeWitt) and secretary Chrissy Snow (Suzanne Somers) are hung over after throwing a huge party for their departing roommate Eleanor, and they are surprised to find a complete stranger sleeping in their bathtub. He turns out to be culinary student Jack Tripper (John Ritter), who crashed the party and had blacked out. After getting to know and like each other, they all decide that Jack should move into Eleanor's room, but that does not sit well with Stanley Roper (Norman Fell), the landlord who does not approve of co-ed living situations until quick-thinking Janet changes his mind by convincing him that Jack is gay. Thus, a farcical premise was born that would likely not play very well in this day and age.
Episodes tended to revolve around ridiculous misunderstandings, sleazy swinging singles-style shenanigans at the Regal Beagle pub, and elaborate pratfalls from Jack. He juggled that pretense in front of Mr. Roper while at the same time fending off advances from his wife Helen (Audra Lindley), who saw through his ruse by Episode 2 but didn't tell Stanley because she considered him a schmuck. This wasn't the kind of show that had "very special episodes."
The Ropers spun off after Season 3, giving Helen and Stanley their own show, while the inimitable Don Knotts joined the cast in Season 4 as the new goofball landlord Ralph Furley, and Jack needed to keep up the gay facade for him, too. Somers left the show after Season 5 amid a contract dispute, and she was replaced first by Jenilee Harrison as her ditzy cousin Cindy Snow, and then in Season 6 by Priscilla Barnes as Terri Alden, a decidedly un-ditzy nurse from Massachussetts.
The show was still popular when it ended in after Season 8 in 1984 and transformed into Three's a Crowd, which began only a week after the final Three's Company aired. and featured Jack Tripper moving with his new girlfriend into a building her father owned. Ritter was the only cast member to transition to the new show, which was developed without the knowledge of the rest of the cast until DeWitt accidentally happened upon the auditions for the new show taking place. That was a not-so-comical misunderstanding, and thus it was perhaps karma that Three's a Crowd only lasted a single season.
Andy Hunsaker has a head full of sitcom gags and nerd-genre lore, and can be followed @AndyHunsaker if you're into that sort of thing.