In The Princess Bride, Vizzini repeatedly exclaims, “Inconceivable!” when events contradict his expectations. The word becomes a comic marker of his overconfidence and inability to accept that his plans can fail.
Vizzini is a Sicilian criminal mastermind who kidnaps Buttercup with Fezzik and Inigo Montoya. Wallace Shawn's emphatic delivery makes the single-word outburst one of the film's most quoted lines. Inigo eventually points out that Vizzini may be using the word incorrectly, adding another joke to the repetition.
Rob Reiner directed The Princess Bride, released in 1987, from William Goldman's screenplay based on his 1973 novel. Cary Elwes played Westley, Robin Wright played Buttercup, and Shawn played Vizzini. The quote is sometimes replaced with “Unbelievable,” but “Inconceivable!” is the film's distinctive wording.