Factual error: The word 'magician' is spelled 'magicinan' on the cart when Nicholas bends down to collect the spiders web. (00:50:30)
Continuity mistake: Lisa is trying to convince Gary's parents to let him go to the party. There is a glass of beer on the table. The camera switches to a close up and then back to a wide shot and the beer is gone. (00:37:49 - 00:39:10)
Continuity mistake: When Sonja and the Queen fight in the candles' room, the ones on the right are thick, and the Queen cuts several of them with her sword. When the Prince enters, not only are the candles fixed and standing up, but they are all thin.
Revealing mistake: You see Scott walking towards the shower and he says hi to Chubby while passing him, but if you look closely after that you can tell Scott's only wearing a mask and his shoulder is bare skin. (01:00:15)
Visible crew/equipment: During the final battle, when the Ewoks swing on the ropes, a crew member's hand is visible pushing one of them forward.
Factual error: When the bishop is told Navarre is back and the bishop from the balcony claps and orders for Cezar, the portico behind the servant has a sprinkler pipe running from the first column to the opposite wall. Kind of advanced for a medieval castle. (00:33:00)