The movie is great. Have you read the book?
What's it about? Lots of reviews use this quote: "Fencing. Fighting. Torture. Poison. True love. Hate. Revenge. Giants. Hunters. Bad men. Good men. Beautifulest ladies. Snakes. Spiders. Beasts of all natures and descriptions. Pain. Death. Brave men. Coward men. Strongest men. Chases. Escapes. Lies. Truths. Passion. Miracles."
(William Goldman can write anything. Books, movies. Read Marathon Man and never go to the dentist again. Read The Season: A Candid Look at Broadway and it will change the way you think about theatre in New York. I could go on. And on.)
The set up of The Princess Bride - young William Goldman is sick and his father reads him The Princess Bride, by S. Morgenstern, a famous writer from Florin. One problem. There is no S. Morgenstern. There is no Florin. Years later grown-up Mr. Goldman has his wife, Helen, a psychiatrist, get the book for their son, Jason. Guess what? They're made up, too.
Just like the abridged (the "good parts" version) of the S. Morgenstern The Princess Bride.
And if the story of Buttercup and Westley and Inigo Montoya and the six-fingered man (I could go on and on again) isn't excellent enough, Goldman interrupts the novel (in red print in some editions) to explain why he's taken out certain sections of the original.
Even if you've seen the movie, it's worth it to read The Princess Bride.
(All the parentheses in this post? Inside joke if you know the book.)