The third season (after Ritter's death) took a creative turn, revolving more around cousin C. (David Spade) and grandfather Jim (James Garner), than the immediate Hennessy family, more specifically not revolving around the raising of the Hennessy girls.
After the novelty of newly added ensemble characters wore off, the series returned to its original format.
Shortly afterwards, ABC officially cancelled 8 Simple Rules in May 2005.
While 8 Simple Rules ratings were well above those of the surrounding TGIF shows during its third season, ABC cancelled it due to the perceived inability to sell reruns of the show into syndication (a fourth season would have given the show the 100 episodes necessary to enter daily syndication).
It aired weekdays from January 2, 2006 to September 15, 2006 when it was replaced by Reba upon the merger of UPN and The WB into The CW.