<p>@GodMode there’s nothing preventing it and when there is a bad essay it is completely appropriate to change it. They are emphasizing the fact that the essay is supposed to be common, which means you shouldn’t submit a different essay for every school- and they prevent that with the limit of 3 different versions. But changing a bad essay to a good one and submitting that to the remaining schools is different, because it is still a common essay, and does not cause any problems- in fact, it fixes many.</p>