For the past 18 years, you have been lucky enough to have a room of your own in a comfortable house. You even had one of those cliche basement apartments – the dream of every high school student.

Never has anyone else bothered you with their choice of music, nor have your sleeping patterns been bothersome to anyone but your parents.

But when your acceptance letter arrives in the mail, you feel something cold and smooth at the bottom of your belly: you’re going to have a roommate.

You could’ve tried to convince your parents that you needed a single room to concentrate and study hard. But you’re actually excited about the prospect.

You’ve seen those movies where down-on-their-luck thirtysomethings meet up with their freshman-year roommates and their lives suddenly have meaning again. Hopes of having a rich, generous and smart roommate that will help you with your homework and failing social life pervade your thoughts. Ignoring your reservations, you accept your fate and pray that Loyola does its best to actually match you up with someone decent.

This is your fatal mistake. Those forms that you filled out this summer are merely the only interesting part of Residential Life’s job. They love to mismatch applicants as often as possible. The tiny book-smart kid with the rambunctious 6′ 10″ metalhead. The left-wing women’s studies major with the Bush-supporting business student. The strong and the weak, the poor and the rich, the clean and the dirty, the combinations are limitless.

It’s important to go into your first few weeks with a little bit of a field guide to some of the more frequent types of misanthropes you may be forced to live with.

No. 1: The Not-So-Bright-But-Friendly Roommate

This specimen is common among the new recruits.

Upon first moving in, you will discover that your roommate has decided to cram the contents of their entire house into your room sized like a prison cell. Numerous household appliances will be plugged into a single outlet, pointless clutter (like beanbags and those idiotic “gaming chairs” from Wal-Mart) will cover your floor, and the trashcans will never be empty.

An odd assortment of bad-smelling characters will be forever parading through your room and hanging out with your roommate, who will think nothing of having a stranger sleep in your bed while you’re in class.

The worse part is that your roommate is one of the friendliest people you have ever met. He tells you to eat his food, use his computer, play his video games and even hit on his girlfriend. What he lacks in brainpower, he makes up with heart. Unfortunately, in college, a benevolent spirit gets you nowhere.

Get rid of this roommate as soon as possible, and get with someone who won’t make your room a fire marshal’s nightmare.

No. 2: The Schizophrenic-and-Stabby Roommate

This is probably one of the more dangerous species of roomies, for their disguises are numerous. Your roommate will greet you warmly with a big hug and make you feel right at home.

But after the first couple of days, during which you will spend relatively few hours in the same room, you will slowly notice that things are amiss. You’ll discover that one sock from each of your pairs is missing, or that your comb has hairs in it that aren’t yours.

It is only after the deadline for changing rooms has passed that the true nature of the beast will reveal itself. Mutterings in tongues will keep you awake for hours every night. You’ll have to dodge empty prescription bottles with each step you take. The bathroom will be locked for hours on end. ABBA will play on a loop.

After months of terror, you will awake one night to the sweaty, misshapen figure of your roommate crouching over you with a pair of scissors, screaming at you for eating the rest of his ramen.

Diffuse the situation by knocking them out with your history textbook and running for your life.

There is nothing redeemable about this roommate. You are at college, not Angola State Penitentiary. Get your resident assistant involved as soon as possible.

With any luck, the men in white will appear shortly, and you’ll have a single room for the rest of the year. Claim emotional damages, and you might even get it for free.

No. 3: The Wannabe-Gangsta Roommate

This one is a classic. A young kid from the North dreams of making it big. He works hard in high school to get into college, drops an application at every school in the country and finally decides to move to the Deep South. He studies the culture by watching Baby Boy Da Prince’s “The Way I Live” video for several hours a day.

Settling into the city after spending the summer with his Dave Mathews Band-listening buddies by the creek back home, he is finally able to achieve his goal: selling cheap drugs out of his freshman dorm room to other just-as-naive students.

He won’t ask for your permission to start slinging, nor will he even let you know how he makes his expendable cash.

Your roommate will start making dangerous mistakes: Sporting a New York Yankees baseball cap casually slung to the side and oversized Chicago Bears jerseys; hanging around Friar Tuck’s throughout the week and wandering down Freret Street with newly acquired “friends:” and taking personal checks for private dealings.

The room will suddenly become a marketplace for glossy-eyed teenagers looking to enhance their video game experiences. Approach the idiot and tell him that you don’t want anything potentially illegal in your room. Explain to him that the cash he makes is not worth the loss of the $10,000 scholarship he has. If he doesn’t comply, then do what you can.

Express the situation to your RA in the simplest of terms. No one likes to snitch, but you owe him nothing, and he’s already put you at risk of losing your scholarship.

Anyone willing to put you at risk is a target themselves.

John Sequeira can be reached at [email protected].