With the eleventh season of It’s Always Sunny in Philadelphia currently airing on FXX, we’ve been thinking a lot about our favorite moments from the series. Many viewers have already hopped on board the crazy train that is the show, but if you haven’t yet, we’ve put together a little background information that should make the transition as easy as a game of Chardee MacDennis.

Your guides on this debaucherous tour are Dennis (Glenn Howerton), Dee (Kaitlin Olson), Mac (Rob McElhenney), Charlie (Charlie Day), and Frank (Danny DeVito), who are collectively known as The Gang, who own (to some extent) and operate (to some extent) Paddy's Pub in Philadelphia. When they get along, it’s wonderful. When they don’t, well, that’s pretty good too.

Here are Screen Rant’s 10 Things You Need To Know About It’s Always Sunny In Philadelphia.

They're Terrible People

Chances are, in the first ten seconds of any given episode, at least one character will say something that confirms this. Occasionally scrutinized for “going too far,” the show only works if audiences understand that the jerks on-screen are doing what they believe is right, and don’t realize the extent of their selfishness. Without this, Sunny just looks like a bunch of narcissists ruining the lives of whomever they meet, and there’s enough of that on the news already.

Now that you’re comfortable with this psychological revelation, you can enjoy their zany antics! Divorce, the recession, welfare, racism, homophobia, and bed-pooping are some of the complex topics these terrible folks attempt to navigate. In the end, The Gang usually fails, but their loss is our win.

They have ruined some lives.

As previously mentioned, The Gang are terrible people. While some characters only have to be on the receiving end of a given hare-brained scheme one time, others have become subjects of prolonged attention. Take, for example, the tale of Matthew Mara, a.k.a Rickety Cricket (David Hornsby).

Known to them since high school, Matthew’s dependence on leg braces earned him the nickname Rickety Cricket. Introduced early as a priest, his life’s potential is crushed by a lingering schoolboy crush he has on Dee. Eventually becoming homeless, he’s sought out by The Gang whenever they need something particularly unpleasant or humiliating done. He’s had a kidney stolen, lived at the dog pound, suffered major burns, and had his legs broken by the mob thanks to them.

Interpersonal Relations

One of the great things about Sunny is the constantly shifting dynamic between the main characters, but the basics never change: Dennis and Dee Reynolds are twin siblings, Frank is their father, and might be Charlie’s too. Mac and Charlie grew up as best friends, and went to high school with Dennis and Dee. Dennis, Mac, and Charlie own Paddy’s Pub, where Dee works as a bartender/waitress/failure. Frank is retired, and often funds the insanity.

None of these alliances hold up the same way from episode to episode. Keeping it interesting, there are often different combinations of characters at war despite blood relation or childhood allegiance. Having said that, it’s pretty safe to assume that no matter what’s happening, Dee can be found at the bottom of the food chain.

Who writes this stuff?

Sunny is a collaboration of many great minds. Created by Rob McElhenney, the bulk of the episodes are co-written by himself and co-stars Howerton and Day. Rickety Cricket/David Hornsby, Scott Marder (Unsupervised), and Rob Rosell (New Girl) have also contributed writing for the series. All of them serve as producers, and McElhenney has even directed some episodes. Matt Shakman (The Good Wife) has the most directorial credits to his name, and child star Fred Savage (The Wonder Years) worked on some of the funniest episodes of the show’s third, fourth, and fifth seasons.

Modern issues are interpreted hilariously through The Gang’s misfortunes, and can often found right in the episode’s title. Like "The Gang Solves The North Korea Situation," "Dennis Looks Like A Registered Sex Offender," "The Great Recession," "Mac Fights Gay Marriage," and "The ANTI-Social Network," to name a few.

Danny DeVito

Despite being met with positive reviews, the show failed to garner enough of an audience for execs to be confident in moving forward with a second season… until Danny DeVito signed on. Pleased with the addition of some star power to the cast, the ratings bump was enough to save the show, and It’s Always Sunny has been gaining traction ever since. It’s premiere on January 6, 2015, marked the start of the show’s eleventh season, and FX has already announced it will return for a twelfth.

DeVito has been a remarkably good sport, too. Frank is a disgusting man, and has been the butt of some pretty elaborate (and nauseating) jokes. One scene required him to crawl, naked, out of a leather couch in the middle of a party, and that is just the tip of DeVito’s dedication to Frank, who’s been engaging in all sorts of debauchery since his very first appearance.

Conflict with the outside world

Part of what makes Sunny so amusing is the bubble in which the characters exist. The Gang’s brand of problem solving is tragic when used in the company of normal people equipped with logic. Outsiders are either a target or a tool, and continue to challenge The Gang’s collective wit. They knock street performers down a peg ("Charlie Goes America All Over Everybody’s Ass"), challenge the criminal justice system ("The World Series Defense"), and generally make the lives of service people a living hell ("The Gang Dines Out").

Occasionally, though, The Gang gets altruistic, banding together to make Philadelphia a safer, cleaner, happier city. They’ve remodeled a poor family’s home, saved a baby from a dumpster, and tackled the homelessness that plagued their immediate vicinity. The execution may be flawed, but it’s the thought that counts… right?

Running themes

Ten seasons is a long time to cultivate running jokes, but new viewers will be lost on some of the more hilarious ones. Depending on who your favorite is, you might be tuned in to one character’s tendencies. The layers of running themes keep the series endlessly watchable, fans picking up on new tidbits with every viewing. Some are a little more outstanding than others, but all are funny.

For example, it’s often noted that Dee looks very similar to a bird. The best execution of this stereotype can be found in “Who Got Sweet Dee Pregnant” wherein The Gang recount the events of a Halloween party in which they believe one of their male members slept with Dee. Throughout the night, her costume, an angel, slowly devolves into a bird in everyone’s memory. Later, she bullies herself into someones peacock outfit, showcasing another theme: Dee inadvertently reinforces everyone else’s opinion of her.

Oh, and the McPoyle's really, really, like milk.

They'll surprise you.

As mentioned earlier, the core characters almost never group together the way you expect them to, which is surprising. But sometimes the characters themselves are the ones to blow us away. Loyal viewers may think they have Charlie Kelly figured out: milksteak, night crawlers, denim chicken. We get used to his illiteracy, and enthusiasm. So when episodes like “Flowers for Charlie” and “Charlie Work” come along, the writers ensure we are delighted by him in a whole new way.

A sexually-confident Dennis faces his insecurities in “America’s Next Top Paddy’s Billboard Model Contest” and “The Gang Reignites The Rivalry.” The episode “How Mac Got Fat” answers the question on everyone’s minds in season seven, and his shockingly well-presented anti-evolution argument in "Reynolds vs. Reynolds: The Cereal Defense" will have you thinking about your own stance on the subject. Dee’s surprisingly active sex life gets picked apart in “Dee Gives Birth,” but we won't spoil the surprise for you here.

Despite all the (very) intimate details audiences have about Charlie, Dee, Mac, Dennis, and Frank, there are still facets of their personas to be explored, keeping the show interesting.

Multiple personalities.

Each member of The Gang is different from the next, and their interactions are peppered with disagreement because of it. Dennis has been described by the co-writers as being a sociopath, Howerton even cites this as the reason his character isn’t named after him. His tendencies generally keep him pretty calm, but on glorious occasion, he is capable of throwing the most epic hissy fits television history.

Priding himself on his sexual prowess, he employs all sorts of tricky behavior (The D.E.N.N.I.S System, namely) to manipulate women. Mac sees himself as the head of security/ultimate badass capable of roundhouse kicking, performing ocular patdowns, and scaling building facades. A rocky relationship with his father may have led to an unhealthy obsession with Chase Utley. Dee, a failed actress, is prone to stage fright and nervous vomiting. She puts up with more than her fair share of trouble from the boys, but is occasionally the aggressor. Frank is a crooked, gun-loving businessman who’s always in for a scheme.

And Charlie, well, he’s a wildcard.

Real-life connections

Charlie’s obsession with The Waitress (Mary Elizabeth Ellis) becomes all the more cute (and far less illegal) when you know they’ve been married in real life since 2006, and have a son. After having met on set, McElhenney and Olson also started dating and got married in 2008, who was very pregnant during the filming of several episodes. The couple have two children. Ironically, Howerton married Jill Latiano in 2009, who audiences will recognize as the pharmacist who gets played in "The D.E.N.N.I.S System." They also have two kids.

In addition to all the relationships woven into the show, Olson and McElhenney actually own a bar in Philadelphia named Mac’s Tavern. Dick Towels, Flipadelphia jerseys, and Kitten Mittens can all be purchased online.

Conclusion

So what do you think of our list? What else do budding fans of the series need to know? Let us know in the comments! And check out It's Always Sunny in Philadelphia, airing Wednesday nights at 10pm on FXX.