In a Halloween episode, Randy gives one piece of candy to a kid dressed as Buzz and a giant handful to to a kid dressed as "the cute little lion cub".
Tim is having a tea party with his nieces. He does all the voices of their stuffed animals, but they complain that he didn't voice the lion right. Tim mentions that he doesn't know what it's like to be a lion. Randy mentions that it was tough. Later in the same episode, Tim is playing with the girls' Buzz Lightyear, and argues with it by claiming "I am Buzz Lightyear...No, I am Buzz Lightyear...No, I am Buzz Lightyear...I come in peace." Tim then presses the button on the toy, causing it to say "I am Buzz Lightyear. I come in peace" in the exact same voice.
Another episode had Tim arguing with his brother. When it descended into "Is too times one hundred!", "Is not times a thousand!", Tim capped "To infinity!" with "To infinity and beyond!", the Catch-Phrase of Buzz Lightyear in Toy Story.
Pamela Anderson (who played Lisa, the original Tool Time Girl) left Home Improvement after season 2 because she was offered a starring role on Baywatch. In Season 3, Tim tells the audience that Lisa quit Tool Time so that she could take paramedic training. In real life, professional lifeguards must undergo paramedic training.
Actor-Shared Background: Patricia Richardson grew up in a military family just as her character Jill Taylor did. Richardson's father, a Naval Academy Graduate, was a fighter and test pilot and later an aeronautical engineer and executive. Her mother was a housewife. The fact Jill Taylor's father also would fly missions was brought up in an episode where Jill discusses her fear of flying with Wilson.
Big Little Brother: Jonathan Taylor Thomas (Randy) is actually older than Zachary Ty Bryan (Brad) but was made the middle child because he was shorter. Eventually, both Bryan and Taran Noah Smith (Mark) would end up towering over Thomas by over six inches.
Contractual Purity: Back in the 70's Tim Allen was arrested for drug dealing and he got his life in order, eventually becoming a successful comedian. Before the show aired a newspaper article tried to drum up a controversy for having a reformed drug dealer as the star of a family show. They responded by telling their side of the story as quickly as possible. Tim Allen also noticed that because of the show more families with young kids would attend his stand-up, so he toned down the adult content. Even today he is largely considered a family-friendly actor/comedian. Unusual for the trope Allen has always been honest and forthright about his past and criminal record, if for no other reason than to be an example of how anyone can turn their life around for the better.
In a smaller degree, Pamela Anderson is a Playboy Playmate on a family sitcom. She was never a big role and merely wore tight clothing instead of revealing clothing.
Dawson Casting/Playing Gertrude: In a minor example, Jonathan Taylor Thomas, who played the middle son Randy, was actually one month older than Zachary Ty Bryan, who played the oldest son Brad. Therefore, Thomas was one year older than Randy while Bryan was the same age as Brad.
Dyeing for Your Art: Casting for Wilson was damn near impossible because of the stipulation he would never show his face, for obvious reasons actors want their face to be seen. Earl Hindman went the entire series without showing his face, even in cast calls, and only revealed it in a special airing after the Series Finale.
Franchise Zombie: The network wanted to keep the show going but everyone involved, including Patricia Richardson and Tim Allen, knew that they had reached their peak at 8 seasons. The last season is generally considered the point when the show was running out of steam. Allen famously turned down a $50 million offer.
Name's the Same: Tim Allen's character is not to be confused with the real Tim Taylor, a longtime news anchor at Cleveland's CBS/FOX affiliate WJW-8 from 1977 until his retirement in 2005.
The Other Darrin: Jill's sister Robin appeared in two episodes and was played by a different actress each time.
Jill was first played by Frances Fisher, but audiences reacted poorly to her performance in the pilot episode; she played Jill as more of an exasperated wife and Tim seemed to be torturing her with his DIY projects. Patricia Richardson took over the role and was a lot more grounded and strong-willed to counter Tim's equally strong personality.
Richard Karn was nearly this, he was originally a temporary actor and character while waiting for veteran character actor Stephen Tobolowsky to have an opening in his schedule. As Karn and Allen had good chemistry together and Tobolowsky proceeded to get even busier, they just made Karn a regular.
Permanent Placeholder: Al wasn't supposed to be a permanent character, but a temporary fill in for Stephen Tobolowsky who was supposed to play the permanent co-host of Tool Time, Glenn. Tobolowsky decided he was too busy and audiences responded well to Al, so they simply kept the character in.
Reality Subtext: The episode involving Brad and pot mirror's Allen's own possession of drugs in his earlier years.
Real-Life Relative: The actress who plays Jill's sister Carrie is married to Richard Karn, who plays Al.
Real Life Writes the Plot: The season 5 episode "Doctor in the House" focuses on Tim Taylor receiving an honorary Ph.D (as a ploy for his alma mater to get additional funding). That episode was written around the time Tim Allen received his honorary Ph.D.
Recycled Script: "Bewitched" the final Halloween Episode of the show, feels very similar to season 3's "Crazy Over You." Both episodes involved nearly the entire cast secretly joining forces to play an elaborate Halloween prank on Tim in retaliation for his crazy amounts of pranks, and both episodes even conclude with similar stingers of Tim getting some minor revenge by playing one last prank on the respective masterminds.
Al's Catch-Phrase "I don't think so, Tim." was originally not meant to be a joke. The joke was Al's deadpan expression to Tim's behavior, and the laughter which followed his line was a surprise.
Al's brother Cal was not played by a professional actor. He was actually a Promoted Fanboy who had an astonishing resemblance to Richard Karn and the production wrote him in.
Unintentional Period Piece: Averted in general. While there are elements of the show that make it undoubtably from The '90s, Home Improvement, in both visuals and humor, has aged rather well, especially in comparison to a lot of the other sitcoms from its era. The lack of topical humor and the Taylors being a working-class family that largely ignored popular trends contributes largely to this. It helps too that the main topics of home repairs, sports and car restoration aren't really subjects that are in constant flux with the times.
Al was originally just a placeholder character for another named Glenn to be played by Stephen Tobolowsky. Tobolowsky was unavailable to shoot the pilot so Richard Karn was brought in as Al to be a fill in character. When Stephen Tobolowsky was still unavailable once the series was picked up Tim Allen urged the producers to keep Karn on as he liked the way they worked together. They agreed and Tobolowsky was let go and Karn was kept on permanently.
Ashley Judd was originally cast as the Tool Girl, which was supposed to be a much bigger role (a college student majoring in psychology who acted as a stand-in for Jill on the Tool Time set), but she pulled out only days before the pilot was shot.