Wild card: (n) a person or thing that could affect a situation in a way that cannot be predicted.

As explained on the TV show "It's Always Sunny In Philadelphia," friend groups/gangs/squads can be divided into the categories of the brain, the looks, the muscle, and the wildcard. In the episode "The Gang Solves the Gas Crisis," the gang devises a plan and gives each other roles. Mac is the brain, Dennis is the self-proclaimed looks, Frank is the muscle, and, of course, Charlie is the wildcard.

Charlie's character is odd to say the least. His ideas come out of nowhere, and his strange customs often leave the gang at a loss for words. Here are some "Charlie-esque" qualities that may help you identify the wildcard of your friend group. Warning: you might be the wildcard.

1. Unhealthy obsessions

Charlie is unhealthily obsessed with his love interest, the waitress, despite the fact that she constantly turns him down. He also loves cheese and will eat it every time it's in his presence. Do you have a friend, or are you the friend, who has weird, unhealthy obsessions with people and/or things? This person is the wildcard.

2. Does the dirty workCharlie cleans the toilets and exterminates the rodents of Paddy's Pub because he's good at it. Also because that work is disgusting, and no one else is willing to do it. Do you have that friend who you trick into doing the dirty work by saying something along the lines of "Please do ____ ! No one can do ____ as well as you can!" That person is the wildcard.

3. Unpredictable

Charlie is unpredictable to say the least. Hopefully your wildcard friend hasn't ripped the breaks out of your car yet. The unpredictable friend can be the most fun because of his or her spontaneity. Unfortunately, the carefree, unpredictable guy can also turn stupid and get your whole gang in trouble. If this sounds like one of your friends, that person is the wildcard.

4. Weird/gross living spaceCharlie lives with a herd of cats, eats cat food by choice, and shares a pullout couch with his friend's dad. Hopefully the wildcard of your friend group isn't this disturbing, but maybe they're hoarders or collect something weird. If someone in your friend group has weird rituals regarding their living space, that person is the wildcard.

5. Will do anythingCharlie is the type of person who never turns down a dare. Though I consider this attribute a strength, people who are like this are also probably crazy. Charlie will do pretty much anything, no matter how bizarre, if his friends back him up on it. If one of your friends will do anything you tell them to do, no matter how gross or stupid, that person is the wildcard.

Now that you've read the list, have you diagnosed yourself as the wildcard? If so, welcome to the club. If not, you just might be the brains, the looks, or the muscle. Good for you, except in my opinion, wildcards are the true MVPs. So, as you evaluate your place in your friend group, it's important to keep one thing in mind: you've gotta let the wildcard do his or her thing.