Continuity mistake: D'Artagnan's three best friends who have known him for over twenty years pronounce his name three different ways. Only the stupid one, Porthos (Gerard Depardieu) gets it right. "Athos" is also pronounced several different ways: either a hard or soft initial 'A,' and with the 'h' either pronounced or silent. Sometimes the name is pronounced different ways in different scenes by the same character.
Continuity mistake: Close to the end of the film, when D'Artagnan is helping everyone escape through a back door of the Bastille, he says "Don't stop until you reach the river" and we see the door opening with all the characters in a particular order. I believe Athos is on the left of Phillippe. In the next shot, we see the same door opening from the outside and now the characters are lined up to exit in a completely different order. Athos is now on the right of Phillippe.
Factual error: The film is set in the year 1662. Louis is supposed to be in the middle of a war against the Dutch. This is actually not correct. The war against the Dutch didn't begin until 1672.
Continuity mistake: When Phillipe is having his mask removed after being rescued from the Bastille, he touches both sides of his face with his hands in a close shot of him. But when it goes to a wider shot of him and the rest of the men, when he turns to look at the water bin, his hands are no longer touching his face. There wasn't time to bring them back down.
Other mistake: When the Musketeers are charging the firing squad at the end, they only have about 20 yards to run which they should cover in just a couple seconds, but somehow it takes them much longer to reach the other men. This is especially noticeable since they're running at full speed. (This has nothing to do with editing or slow-motion, as most of the shots are shown in real time, at regular speed.)Krista
Continuity mistake: When Louis hits Phillippe when they are in the Palace, it seems he hits the right side of his face, but Phillippe falls holding the left side.