Audio problem: On Naboo, when they are planning to take over the palace just after the Queen asks R2 to project the map of the palace - watch her lips, they aren't in sync with what she says. (01:39:20)
Other mistake: During the fight scene in the Theed hangar, several times the droidekas (destroyer droids) are shown shooting, but no lasers come out of their guns. (01:46:40)
Continuity mistake: During the fight against the Trade Federation Droid Control Ship, Anakin says, "Okay, let's go left" and turns the controls of his spacecraft to the left. The ship turns left. A few shots later, Anakin says, "I'll try spinning, that's a good trick" and turns the controls to the left, but this time, the ship turns right. (01:49:30)
Audio problem: Where Natalie Portman and some of the security detail are fighting in the Palace corridors, her shiny weapon makes a distinct noise and the normal blasters makes a different sound. Later, she is given a regular blaster to get up the outside of the Palace. However, when she fires that gun to break the window they've ascended to, it makes the same noise as her shiny blaster, not the sound of a normal blaster. (01:50:31)
Continuity mistake: Right before Darth Maul kicks Obi-Wan off the walkway, there's a wideshot where Obi-Wan and Qui-Gon are fighting Maul on a straight part of the walkway. In the following shots, all three of them are suddenly standing on a round part of the walkway. (01:50:45)
Continuity mistake: After Obi-Wan falls off the walkway, he manages to grab hold of the edge of another walkway, and on the floor, there's a lit strip near his hands, to his right. When Qui-Gon and Darth Maul continue the fight, there's a wideshot where Obi-Wan (still hanging from the edge of the walkway) can be seen in the lower left hand corner of the screen. His hands are now further away from the strip, and are closer to the strip on his left. (01:50:50)
Continuity mistake: When Obi-Wan falls off the walkway during the duel with Darth Maul, his lightsaber lands on a lit strip of the floor. A few shots later he jumps up and retrieves his saber, which is now resting on a dark area on the floor. Even if the saber continued to roll on the floor between the shots, it couldn't have ended up in this position. (01:50:50)
Continuity mistake: When the three Droidekas appear and attack Padmé's group, in the background you can see that Darth Maul has already ignited his lightsaber. After Anakin says "We gotta do something, R2", the Sith ignites his lightsaber again. (01:50:53)
Continuity mistake: After Darth Maul falls off the walkway, Qui-Gon jumps down after him, and there are several vertical beams behind them. In the next shot, they have suddenly moved past them, but in the following shot, they are fighting in front of the beams again. (01:51:05)
Other mistake: When Darth Maul and Qui-Gon are fighting in the corridor filled with rays, when Maul spins around in the beginning of the second shot, half of his lightsaber disappears for a few frames. (01:51:25)
Continuity mistake: When Obi-Wan, Qui-Gon, and Darth Maul get cut off from each other in the corridor and Qui-Gon kneels down, Obi-Wan is standing in the background with his lightsaber pointed downwards. In the next shot, it's pointing upwards. (01:51:45)
Continuity mistake: As Obi-Wan is looking up at Darth Maul and Qui-Gon, they are fighting in the middle of the walkway. When Obi-Wan jumps up, they are at the doorway at the end of the walkway. They couldn't have reached the end of the walkway that quickly. (01:51:50)
Continuity mistake: When Amidala and some other guards use the ascension guns from the palace windows seven of them go up, when they are running along the corridor after coming off the window-ledge, there are about 13 or 14 of them. Then finally when they are surrounded by the droids, there are about 10 or 11 of them and Captain Panaka is not there. (01:53:30)
Continuity mistake: When Qui-Gon dies, you see him fall down - his hands clearly hit the ground and rest there after sliding off his body. In the close-up shot, Qui-Gon's right hand does not and rests on his stomach. (01:55:00)
Continuity mistake: When Qui Gon is killed, he falls to the floor with his right arm on the floor. The next shot shows his left arm falling and his right arm on his chest. (01:55:05)
Continuity mistake: Just before Obi-Wan jumps up from the pit, there's a shot of Qui-Gon. His lightsaber, which was lying on his left side after he was stabbed by Darth Maul, is now lying below his feet. (01:55:10 - 01:59:00)
Continuity mistake: Qui-Gon, Obi-Wan, and Maul are fighting in one of the bridges in the reactor room. In the next shot, when Maul kicks Obi-Wan, the three are now fighting next to a reactor. (01:55:28)
Continuity mistake: Qui-Gon kicks off Darth Maul with his lightsaber ignited. In the next shot, when he jumps to fight the Sith, the lightsaber is turned off, even though the turning off sound is never heard. (01:55:45)
Continuity mistake: Before the pod race begins, as Jabba the Hutt says, "Welcome.", the woman to his right has her hand on the wall. In the next shot, she is no longer touching the wall and her head is turned in a different direction. (01:56:00)
Continuity mistake: In the chamber room near the end of the movie, after the Queen throws the guns to everyone and goes to address the Viceroy, she starts to walk away from her chair. While she is doing that, you can distinctly see her lose her footing and slip on the floor. In the next edit she repeats this movement without slipping. (01:56:10)
Chosen answer: According to "Inside the Worlds of Star Wars: Episode I" by Kristin Lund, they are "laser doors which lock into position in response to potentially lethal power outputs that occur intermittently during plasma activation process" (the fight takes place in a plasma energy processing plant). There are six laser doors in deference to an ancient Naboo legend in which Chaos is held back by six inpentrable gates. As you say though, they're really just a plot device to add dramatic tension to the duel!
Sierra1 ★