Odds are they don't, but many legal writers fall into the habit of using them. In those rare instances when a common word cannot be substituted, quickly define the word when you first use it, and then move on. Finally, be aware that readability is not just a function of how you write. The appearance of your text also matters. Readability studies have shown that typeface styles and sizes affect comprehension.
Typefaces come in two basic types, serif and sans serif.
A serif typeface has small lines at the beginning and end of each letter. Sans serif typefaces lack the small connective lines. Serif typefaces are easier to read than sans serif typefaces because the small connective lines quickly lead your eye from letter to letter. Avoid sans serif typefaces such as Courier. Good serif typefaces to use are Times Roman, Garamond, and Century Schoolbook.