In a recent interview, renowned comic actor Danny DeVito revealed that the creators of It’s Always Sunny in Philadelphia managed to write a script even he thought went too far. Of course, by this point, DeVito’s Frank Reynolds is a key part of the show’s ensemble and of its humor. However, he wasn’t actually present in the first season.

In fact, there are so many things that have changed from the early days of the series that, in some important ways, it’s almost unrecognizable. For this reason, it’s worth taking a look at some of the most notable of these in order to truly appreciate what it has become.

The Lack Of Themed Episodes

The Paddy's Pub gang perform the Nightman cometh on stage in Its Always Sunny In Philadelphia

Like many great series, It’s Always Sunny sometimes breaks away from the sitcom format to give audiences various themed episodes. In doing so, it flexes its own creative muscles. Episodes such as the spoof of film noir or the musical are reminders of just how comedically skilled the series remains.

However, this is a convention that was only established after the first season. In fact, it’s hard to imagine the first season having any episodes like this, considering the fairly limited conception of what the show was in the very beginning.

The Absence Of Frank

Frank in a hoodie and green shirt in It's Always Sunny in Philadelphia

Frank Reynolds is arguably one of Danny DeVito’s best roles. He has become such an integral part of the show and so seemingly at ease with performing numerous disgusting acts, that it is truly difficult to imagine the series without him.

In fact, watching the first season, it is clear that something is missing. While some of this might simply be the benefit of hindsight, it has to be admitted that adding DeVito was one of the best decisions the series ever made, and it helped to elevate it into one of the great sitcoms.

Dennis Is Far Less Unhinged

Dennis angrily shouts in front of a port in It's Always Sunny in Philadelphia.

When the series begins, Dennis is, like both Mac and Charlie, capable of very bad behavior. However, as reprehensible as he might be, he’s not anywhere close to the person he would become just a few seasons later.

It has become so well-established that he is most likely either a sociopath (or even possibly a serial killer) that it’s hard to see the character in the same way. He’s not exactly likable, to be sure, but neither is he the terrifying person–prone to outbursts of rage–that he will later slowly but surely develop into as the series progresses.

Charlie Is Far More Intelligent

Charlie looking concerned in It's Always Sunny In Philadelphia

It’s safe to say that Charlie is not one of the series’ most intelligent characters. It is made abundantly clear throughout the last few seasons that he is barely functional, in part as a result of his tendency to drink cleaning fluids.

In the first season, however, there is very little of this to be seen. He may not be the most intelligent person, but the show also doesn’t make a point of highlighting those things which would come to characterize his later persona. Instead, he just seems about as hapless as Dennis and Mac.

Dee Is The Voice Of Reason

Dee eating cake in It's Always Sunny.

One of the most notable changes that occur between the first season and its successors is the character of Dee. In the beginning, she is something of the voice of reason, the person who is willing to take a step back.

This marked her as very different from her male counterparts and, truth be told, a waste of Kaitlin Olson’s formidable acting talents. She is a little bit boring in the first episodes of the series, so it is definitely a good thing that they slowly let her character become as prone to terrible behavior as the others, with all of the physical comedy this enabled.

There’s More Focus On The Bar

The Gang at Paddy's Pub in It's Always Sunny in Philadelphia

By this point, it’s clear that much of the humor in It’s Always Sunny stems from the various schemes the Gang gets into. This is so tied up with the show’s fundamental identity that it’s hard to imagine it without it.

This was not at all true in the beginning, however, when there was a much stronger emphasis on Paddy’s Pub and what it took to run a bar. Given just how zany these schemes have become and how skilled the show is at mining these scenarios for uproarious humor, this is a change that has been for the good.

A Lack Of Extremely Problematic Episodes

The Gang in a car in It's Always Sunny in Philadelphia.

With each new season, It’s Always Sunny has shown a willingness to truly push the envelope, creating very cringeworthy moments. It’s for this reason that it should be regarded as both a great sitcom in its own right and one of the best series on FX.

Notably, however, there is a notable lack of truly problematic episodes in the first season. Compared to what will come after, the first season is almost boring. It’s a clear sign that the show was still finding its footing and trying to decide just what kind of a series it would end up being.

Far More Primitive Production Values

Charlie holding his face in It's Always Sunny episode Charlie's Home Alone

Given how much of a success It’s Always Sunny has become, it would make sense that it has come a long way in terms of how much money it has been given. One of the most unrecognizable aspects of the first season, in particular, is how primitive the production values are.

It’s not bad, per se, but it’s clearly a show that has not been given a large budget to play with. It has the feel and the look of a low-budget independent comedy movie, and it wouldn’t be until later that it would attain the polish of one of its home network’s flagship series.

The Characters Aren’t Nearly As Distinct

its always sunny the gang recycles their trash

One of the things that make It’s Always Sunny such a hilarious show is its characters. Each of them, as the seasons have gone on, has become quite distinct. However, this wasn’t nearly as much the case in the first season.

The characters as they emerge here are, in some key ways, very similar to one another, with just enough personality characteristics to tell them apart. As it slowly found its feet, however, it also allowed each member of the cast to imbue their characters with the traits with which they would become so identified.

The Absence Of Cricket

Charlie taking to Cricket on the sidewalk in It's Always Sunny in Philadelphia.

Like all great shows, It’s Always Sunny has excelled at creating compelling side characters. Perhaps none of these is more important than Cricket, who has had to endure unspeakable things at the hand of the Gang. In the first season, however, he is nowhere to be found.

Given just how humorous–and tragic–he would become in the later seasons of the show, his absence is particularly notable. It’s also a further sign of how, during its first season, the show didn’t yet know just what direction it was going to take with its humor.

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