Thesaurus/fancy words.
I believe I might have found a role-player who uses the dictionary/thesaurus as her bible in role-playing. Of course, it's essential for any writer to have a dictionary/thesaurus on hand for any grammatical errors and words that you can substitute to spice things up for your writing, but you know how they say too much of a good thing could end up turning bad? If you constantly have to refer to the dictionary/thesaurus for out of the ordinary words to make your writing look elite, elegant, superior, etc., honestly to me I can't take the time to sit around, decipher paragraphs that have words/structures I've never seen/heard before, and have an enjoyable time threading with you.
I realize that each and every person has their different techniques and style with writing (because yeah, that's obviously a given), but to be honest, I can't stand it when someone uses a constant array of thesaurus words and fancy words that are more distracting and confusing than comprehending to the writing (which to those players, if you quizzed them on the spot about all these fancy words, they probably wouldn't even know their definitions themselves off the top of their heads, sans dictionary/thesaurus, and bet you they wouldn't!) And this is when these "big words" are used more than three times in a sentence, and used more than seven in a full paragraph. Several times I had to read over a sentence twice from this particular writer just because I went, "what the hell are they trying to refer to again?"
My publications teacher from middle school taught us long ago that "fluff words" could be the destruction of writing, both for people to comprehend and for someone to convey an idea or thought. Even after all this time, that was one tip of writing that has stuck with me. While it's great to expand your vocabulary and implement new words into your writing to make it more lively and interesting, like I said too much of a good thing could turn out bad.
That's just me. :P