We wanted to make sure fuzzy RDD is possible in Mplus. We believe it is, but have not actually ever implemented it in Mplus, so wanted to double-check. See http://ies.ed.gov/ncee/pubs/20084026/chapter_4e.asp for a general definition of fuzzy RDD. If so, are there examples of fuzzy RDD in Mplus, as we could not find any?