Looking through the book of quests, the booker finds "the ark of the covenant" and then adds, "That's reserved for the chap with the hat and the whip."
On the board a picture of the flux capacitor is drawn, additional Christopher Lloyd as a teacher who was the Doc Brown in "Back to the Future" and invented the flux capacitor
The pawnbroker (Wallace Shawn) offers Jack some iocaine powder but then reconsiders, saying, "It's very poisonous." In "The Princess Bride," iocaine powder is what killed Vizzini, Shawn's character in that film.