I bet it wouldn’t be breaking news if I told you that you are not allowed to use swearing words when writing an essay. Anyways, some people do attempt to use slang while they accomplish the orders, so that the paper would look more vivid. If I was writing this article five years ago, I would strictly recommend against such methods, but right now I am willing to reconsider. There are certain cases, when slang could be used in academic texts.
If you are lucky enough to take the literature course, you may use slang when you are accomplishing your creative writing assignment. Surely, it is only appropriate if you wish to impose a special atmosphere on your paper. You should also bear in mind that if a teacher asked you to accomplish your creative assignment by using a special style, this style may be absolutely incompatible with modern slang. All the same works for narrative essays.
You most certainly can use slang, if your paper is dedicated towards its study. Not in the body of the essay itself, anyways, but you sure can use extracts from various texts and also describe and explain the terms, which can be barely familiar to tutors.
Slang should not be used in “serious” academic assignments, like thesis papers, research papers, term papers or lab reports. Jargon is also something you should avoid – it is much better to use full forms of the words than their professional reductions or synonyms. For academic authors it is also important to remember – if you may use slang when accomplishing the writing order, please pay attention, what country or what region the order came from. If you got an order from an American student, by using British slang you will doom him to bad grades.