The Three Musketeers (1973)

Continuity mistake: At one point D'Artagnan reaches the Duke of Buckingham, who is on a hunt. He has just killed a stag and his hands are covered in blood. D'Artagnan rides up and offers him a note from Queen Anne. He wipes his palms with a cloth before he takes the note, but his hands are still covered with blood up to and above the wrists. When he reads the note, he and D'Artagnan take off on foot for his castle where they go into a private room behind the walls. Suddenly it is apparent that his hands are perfectly clean right down to his scrubbed fingernails and, without explanation, the plot-heavy sequence continues.

M. Bonancieux: The Bastille! Well, I tell you, I don't want to go to the Bastille! Because it's got very deep dungeons and terrible instruments of torture operated by very unsympathetic men! And they snip very important parts off people.

Trivia: Oliver Reed almost died when he was stabbed in the throat during filming of a swordfight scene.