After a hiatus, the series returned and continued without Ritter, with the producers deciding to kill off Paul and not replace him.
James Garner and David Spade later joined the main cast as Cate's father and nephew, Jim Egan and C. Barnes, in an attempt to fill the void left by Ritter.
The first season focused on Paul being left in charge of the kids after Cate takes a full-time job as a nurse, with comedic emphasis on his often strict rules concerning his daughters and dating.
The series' name and premise were derived from the book 8 Simple Rules for Dating My Teenage Daughter: And Other Tips from a Beleaguered Father (Not That Any of Them Work) by W. While 8 Simple Rules was renewed for a second season and production had begun, Ritter's sudden death in September 2003 left the series in an uncertain position.
The 54-year-old had been rushed to hospital straight from a rehearsal for 8 Simple Rules For Dating My Teenage Daughter.
The final series, its title trimmed down to 8 Simple Rules, ended in 2005, having won a cinematography Emmy in 2004.
The show’s production was shut down to give the cast and crew time to grieve and also to give the network and producers time to decide if and how they should proceed. Cate is waiting for Ed to call her when Rory comes into her office, depressed.
The trouble is that they’re now a trio of independent teenagers — popular Bridget (Kelly Cuoco), brainy Kerry (Amy Davidson), and smart-aleck Rory (Martin Spanjers).
Sagal portrayed his wife, the family's voice of reason, Cuoco his eldest daughter, the stock ditzy blonde.
Ritter, an icon in the world of American television for his star turn on Three's Company, died in 2003 from a misdiagnosed thoracic aortic aneurysm.
On Thursday, she uploaded an Instagram photo of herself reuniting with the original cast of the ABC programme 8 Simple Rules For Dating My Teenage Daughter - except, of course, for the late John Ritter.
Her black-and-white snapshot showed the 30-year-old leaning into frame and grinning broadly alongside Katey Sagal, who played her mother, as well as Martin Spanjers and Amy Davdison, who played her younger siblings.