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: Near the end, when Red Sonja and Queen Gedren are sword fighting, the scar on Gedren's right cheek is missing.
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.
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)
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)