Continuity mistake: The kitchen changes from episode to episode, when viewed from the living room. If the set is going to be used the full kitchen is visible when viewed. But if it is not being used, often the set is pushed closer together. This is most evident when an actor is coming out of the kitchen the stove and the attached cupboards are practically at the door, providing just a bit of space for the actor to stand before making their entrance. Other times a wall is simply pushed up beside the door with the kitchen wall paper on it to appear to have continuity. This is only seen when the shot allows the kitchen set to be obscured.
Continuity mistake: In the very first episode, there is a silver light fixture hanging from the ceiling in front of the kitchen. The light fixture appears and disappears throughout the first season.
Continuity mistake: After Jack brings the puppy over to the girls, the box he brought the puppy in was placed on the back end of their couch. At one point, it is knocked over, and you can see it falling down to the floor (past Janet). In a few shots, it's back on the table, and none of the characters were in a position to pick it up to place it back there.
Continuity mistake: While Jack is talking to the police officer about the missing rent money, they are standing in front of the TV set and the front door is open. When it cuts back to Jack and the officer, over Jack's shoulder the front door is closed, but when the officer turns to leave the door is open again.
Continuity mistake: When Mr. Roper tries to explain to the girls and his wife what he was doing in Jack's bedroom, watch over Mr. Roper's left shoulder on the shelf. The number of yellow cans on the shelf keep alternating between one and two cans throughout several minutes. In addition, also notice the suitcase on the floor under the shelf as well. Whenever one yellow can is shown, the suitcase is by itself and whenever two yellow cans are shown, there is a square silver bag in front of the suitcase.
Continuity mistake: When Mr. Roper does the card trick. Mrs. Roper says it's the 2 of clubs. We see it is. A second later we can see for a second it's a face card.
Continuity mistake: During the kitchen scene when Janet is eating the egg salad sandwich, her yellow napkin is tucked in her blouse and then disappears. She then tucks another yellow napkin into her blouse.
Good Old Reliable Janet - S3-E2
Continuity mistake: When Janet and Mrs. Roper are found nude behind the bushes, Larry leaves to get towels. However, the yellow towel suddenly appears briefly on screen several seconds before Larry returns.
Handcuffed - S4-E18
Continuity mistake: When Jack is eating cake and Chrissy is under the table her the sleeve of her right arm is down. When Jack and Chrissy exit the kitchen into the living room, both of her sleeves are down.
Continuity mistake: When Furley enters The Apartment at the start of the party, the outside weather is crystal clear. Less than 2 minutes later, Furley tells "Austin" the fog is very heavy and the airport is closed down. Then upon opening the front door, tons of thick fog is all over outside. While fog can roll in very quickly, how could Furley even bring up the fog in the first place when it was not there at all when he walked in?
Continuity mistake: When Jack is on the phone explaining why he can't go into work again because he's really hiding at home from the bully Max, there is a chair wedged up against the front door. Larry knocks and when Jack is sure it is indeed Larry, he unlocks and opens the door without the chair in the way any more.
Jack Bares All (a.k.a. Oh, Nurse) (2) - S6-E2
Continuity mistake: In the scene where Terry puts on the gag glasses, notice how the black circles under her eyes get larger after the shot changes.
Gigolo Jack or Professor Jack - S6-E4
Continuity mistake: In the scene where Terri admits to Jack that she mistook his cooking lessons for lovemaking lessons, look at Terri's bangs. They go from on her forehead to brushed back then back to on her forehead then back to being brushed back.
Continuity mistake: In the scene where Jack, Janet and Terri are on the air for the cooking show, Janet holds up the silver bowl but there is no parsley in it. Then in the next shot the bowl is instantly full of parsley.
Continuity mistake: In this episode, Larry is a really poor sounding singer, but in the episode "Strangers in the Night (6-12) " in the previous season, Larry sang perfectly without any problems.
Continuity mistake: After Furley tells Jack about picking up the pot, he says, "Of course, it'll cost you." Later, when the cop listens to the recording of the conversation, the tape has Furley saying, "Of course, it's gonna cost you."
Jack Goes the Distance - S7-E16
Continuity mistake: In many earlier episodes, Jack always mentions he was a boxing champion in the navy. But in this episode, Jack admits he lost every fight in the navy.
Continuity mistake: In episode 8-3, they got a new couch. In this episode, the old couch is back. (00:05:01)
Suggested correction: Many episodes in Season 8 were aired out of sequence from how they were actually filmed. The production code for this episode was 801, and the code for the episode where they got their new couch was 804 (made 3 episodes later - even though it was actually aired first).
Continuity mistake: When the painting of Jack is hanging in the Regal Beagle, the painting is just legs, and not Jack's whole body. In some shots the top of the painting can be seen.
