in huck finn what is the royal nonesuch? what makes it a scam?

Check these sites.

http://www.gradesaver.com/the-adventures-of-huckleberry-finn/study-guide/section5/

http://www.enotes.com/finn/q-and-a/what-royal-nonsuch-means-also-when-young-one-51301

In "The Adventures of Huckleberry Finn" by Mark Twain, the Royal Nonesuch is a fake theatrical performance staged by a couple of con artists who go by the names of the Duke and the King. They claim it is a Shakespearean tragedy, promising a grand show that guarantees a deeply emotional experience for the audience.

However, the Royal Nonesuch turns out to be a complete scam. The Duke and the King set up a makeshift stage, charge admission fees from the townspeople, and gather a large audience. But when the performance begins, the audience realizes that they have been deceived. The Duke and the King simply present a ridiculous, low-brow, and nonsensical act, consisting of crude humor, vulgar gestures, and offensive antics. It is essentially a tasteless and disrespectful mockery of the townspeople's gullibility and their willingness to pay for entertainment.

The scam lies in the fact that the Duke and the King exploit the people's curiosity and desire for entertainment, using false promises to lure them in and make money off of their unsuspecting victims. The Royal Nonesuch demonstrates the wickedness and immorality of these two characters, as they take advantage of people's trust and exploit their naivety for personal gain.