It's Always Sunny in Philadelphia
Continuity Nod in this series.- In the episode where the gang goes on a road trip, Charlie reveals he has never left the city of Philadelphia in his entire life. When they near the city limits he panics and abandons the trip. Several seasons later in "The Gang Gets Stranded In The Woods", they have him locked in the trunk of their car to keep him from escaping when they go to a party outside the city. This is referenced again in "The Gang Goes to the Jersey Shore", where the gang decides to hit the Shore but first discuss the logistics of knocking out Charlie.
- If a character suffers a bad injury in one episode, it usually carries over into the next.
- The gang apparently only has one VHS cassette that they tape over constantly. Whenever we see footage they've recently recorded, snippets of recordings from past episodes play in the blank spots between edits.
- In "Mac and Charlie: White Trash", Charlie wears cutoffs and shows Mac their "advantage"—the ability to pull a wider split, which Dennis showed him in "The Gang Gets Extreme: Home Makeover Edition".
- In "Frank's Pretty Woman", when the eponymous hooker suddenly starts smoking crack, Dennis gets extremely uncomfortable and quickly leaves the room, implying that his addiction from "Dennis and Dee Go on Welfare" is still a problem. Later he talks about how amazing crack is and how much he wants another hit.
- The episode "Mac is a Serial Killer," Dee is approached by a pimp named Pepperjack in a park. He says that she could be his "top ho" if she would just "get up off that crack rock." Dee responds "I'm not on any crack rock! Well, there was that one time..." referencing the episode "Dennis and Dee Go On Welfare" where Dennis and Dee intentionally get addicted to crack to get more welfare benefits.
- In "Frank's Pretty Woman", Roxie's client "Tiger Woods" is actually the same actor hired to impersonate Donovan McNabb in "The Gang Gets Invincible".
- Charlie's small forearm tattoo that he started giving himself in "Dennis and Dee Get a New Dad" is apparently present from that episode forward, though no one ever remarks upon it and it was only established in a blink-and-you'll-miss-it close-up to begin with. It reads "BAD NEW," apparently having been intended to read "BAD NEWS" but never completed.
- In "The ANTI-Social Network" and "The Gang Beats Boggs," Frank calls himself Dr. Mantis Toboggan, the alias he used in "The D.E.N.N.I.S. System."
- Also in "The ANTI-Social Network", after being shushed by a stranger, Dennis remarks that the stranger didn't know who he was, and how he might be a man with a "trunk full of duct tape and zip ties". Come "The High School Reunion Part 2: The Gang's Revenge", it's revealed that Dennis does indeed have a secret compartment in his trunk full of duct tape and zip ties.
- "The High School Reunion" is a Continuity Cavalcade, with references to Mac's dog Poppins and a number of minor characters and events from previous seasons.
- In "Charlie and Dee Find Love," Mac mentions the wrestler "The Maniac" from "The Gang Fights for the Troops" and says he has to get "greased up," which the Maniac announces in the episode. The Maniac also returns in "Mac and Dennis Buy a Timeshare."
- In one episode, Dee wants to go to a Josh Groban concert and meet the guy. She says she wants to "pop" because he loves his ladies to "pop". In "The Gang Saves the Day", Dee fantasizes about marrying him and one of the reasons he likes her is stated to be because she pops.
- In Mac's dream heaven in "The Gang Saves the Day," he sees Rex, the male model about whom Mac said, "His bird won't quit." Rex also shows up in "Ass Kickers United: Mac and Charlie Join a Cult."
- In the episode "Paddy's Pub: Home of the Original Kitten Mittons," Dennis, Mac, and Frank make a marketing video for a marketing convention. At the end of the tape, it is shown that the video was taped over the old video of Dee catching fire while trying to rescue a box of kittens.
- For that matter, the gang keeps going to the same lawyer, to the point that he goes "Aw, no!" whenever he sees the gang in his office.
Lawyer: You do realize there are other lawyers in Philadelphia, right? - In Season 16, Frank mentions that he is no longer homophobic because he saw Mac do his dance.
