Subtlety

noun

1. The quality of being subtle.
2. An instance of being subtle, a subtle thing, especially a subtle argument or distinction.

   "The subtleties of this overture are often overlooked."

3. An ornate medieval illusion dish or table decoration, especially when made from one thing but crafted to look like another.

   "At the king's coronation feast, several subtleties were served between main courses."

4. The quality of being clever in surreptitious or deceitful behaviour; an act or argument that shows this quality.
5. A trick that creates a false appearance.