Over the past 14 years, FX’s It’s Always Sunny in Philadelphia has gone from a lo-fi situation comedy with a cult following to a pop culture sensation with millions of fans across the world. The series is now 13 seasons in, with another one on the way, and one of the most surprising things about the show’s longevity has been its ability to remain fresh and unpredictable after all these years. It has done this by continuing evolve, shaking up its formula, and more importantly, developing its characters.
Dennis is a full-blown sociopath
In the first season of It’s Always Sunny, Dennis was characterized as the everyman. He was just a regular guy who we could all relate to. But over the next few seasons, he would quickly devolve into a full-blown sociopath. He has intricate systems to trick women into bed, he flies off the handle and launches into an angry tirade every five minutes, and he considers himself to be a “golden god” to whom the rest of the human race are just brainless minions. According to Glenn Howerton, who plays Dennis and also writes for the series, this was always planned from the beginning – they just didn’t want to go all the way with it in the first couple of seasons.
Mac is a devout Christian
Mac’s religious beliefs are a huge part of his character, but he didn’t mention his faith in the first season. In fact, in the season 1 episode “Charlie Wants an Abortion,” he used an anti-abortion rally to get laid, displaying absolutely no regard for the Christian side of that debate. His relationship with God wouldn’t even be mentioned until season 2’s “The Gang Exploits a Miracle.” Later in the series, we’d see him drag the Gang to church, take them on a Christian cruise, demand that a giant, bloodied crucifix be put up at the back of the bar, and make them listen to him recite Biblical passages for hours on “Mac Day.”
Charlie has gone off the Waitress
For years, It’s Always Sunny had a running gag in which Charlie pined after “the Waitress” – whose real name even he doesn’t seem to know – and the joke was that she never wanted to be with him in a million years and he just continued to stalk her.
However, to many viewers’ surprise, they actually got together at the end of season 12 when the Waitress wanted a baby. And immediately, Charlie went off her. She was always calling him and asking him about his day and he was sick of it. 12 years of stalking went down the drain. It was a hilarious payoff.
Dee is funny now
In season 1, Kaitlin Olson’s Dee isn’t very funny. She doesn’t make a lot of jokes, she doesn’t get involved in the Gang’s hairbrained schemes – she’s just “the chick.” However, in recent years, she’s become just as funny and reckless as the other characters. According to Glenn Howerton, Olson is to thank for this: “We didn’t want a typical ‘the girl is the straight guy and the guys are the crazy ones who the girl doesn’t get to be as funny as’ show. We knew we didn’t want to do that, but we didn’t know how. When we cast Kaitlin, she brought so much to it in the first season that we were able to figure it out, and figure out what was funny about her.”
Dennis doesn’t smoke anymore
Rewatch a season 1 episode of It’s Always Sunny and one of the most surprising things will be that Dennis is smoking a cigarette in a lot of the early scenes. This is a guy who would later utter the words, “My nose was chiseled by the gods themselves, Frank. My body was sculpted to the proportions of Michelangelo’s David.” There’s no way that guy would fill what he sees as a perfect body with tar. He literally views himself as a god. He goes for days on end without eating and claims to be in constant motion to make sure his body is in tip-top shape. The Dennis we know now wouldn’t smoke.
Mac actually is ripped
One of the biggest surprises in season 13 of It’s Always Sunny was that Mac finally got as shredded as he’d always thought he was. Earlier in the show’s run, there was a running gag revolving around Mac’s body image. He wasn’t in bad shape, but he thought he was enormous, built like a bodybuilder. At one point, he called himself a “muscle-bound freak” and the joke was that he was completely delusional about what his body looked like. This led to a season in which he was fat (or, rather, “cultivating mass”) and, more recently, a season in which he actually was in incredible shape.
Dee is constantly doing accents and wearing costumes
Originally, Dee was an aspiring actress in name only. In season 1, it was just a vague character trait to round her out a little bit, but it wasn’t a part of her storylines. She never went to auditions, we never saw her doing monologues in the mirror – she just spent a lot of time talking about her dreams of being famous.
However, in later seasons, the writers found a way to make this part of her character funnier by having her put on terrible accents and do extremely off-the-mark celebrity impressions. She also plays outrageously offensive comedy characters and wears costumes all the time.
Charlie’s mental health has rapidly declined
In season 1, Charlie was just the childlike guy who couldn’t read and was hopelessly in love with a girl who wanted nothing to do with him. For all intents and purposes, he was a pretty average guy – he was just really immature. However, later seasons have really dug deep into Charlie’s psyche. He bit a mall Santa that he suspected of having slept with his mom. He spends his spare time sticking cat fur to his skin and pretending to be a cat. He constantly huffs glue, paint, and all kinds of other substances. The list goes on and on.
Mac identifies as gay
Nobody expected this to happen. While Mac was depicted as straight in the first season, as the series went on, it became clearer and clearer that he was very confused about his sexuality. The rest of the Gang had even mentioned a bunch of times how obvious it was that Mac was gay, but it didn’t seem like he would ever come out – and then, shockingly, in the “Hero or Hate Crime?” episode, he did. The storyline with Mac’s sexuality culminated in a breathtaking dance sequence at the end of the season 13 finale. What began as a running gag ended with one of the most emotionally charged scenes in recent TV history.
Frank has joined the group
After the first season of It’s Always Sunny was a cult hit, but stumbled in the ratings, wary FX executives brought in Danny DeVito to join the cast for season 1. Initially, he was playing Dennis and Dee’s father, Frank Reynolds, who acted as a sort of soft father figure for the Gang. However, he has evolved over the course of his time on the show into a human monster who is even more depraved and deplorable than the rest of the Gang. It goes without saying that the show wouldn’t be half as great if it weren’t for DeVito’s hilarious contributions.
