Before you get all indignant about what I’m about to say, let me start with this: a good movie must have “logic” applied to the design of its story world. This doesn’t always mean the logic of science and physics as we know it. In fact, more often it means logic based on rules established by the storytellers -- especially when it comes to fantasy genres. For instance, while making the original Star Wars films Lucas made it clear to the conceptual artists that every piece of tech (be it a ship, moisture vaporator, laser rifle) must have logic to it. He wanted the audience to see how these things worked.
My first thought when seeing that stupid lightsaber was, “How could anyone fight with that thing without slicing off their hand?!” Instantly, the logic is gone because I can’t see or understand how the thing would work.
Some of my more nerdy/analytical friends have refuted my claim. I say there’s a line that shouldn’t be crossed when it comes to the Suspension of Disbelief, a line which I believe the lightsaber design crosses. I say its design is “cool for the sake of cool.” My friends say otherwise.
Here are the most popular arguments and my responses.
The "Maybe You’re Over-thinking It" AngleThe argument: If you think too much about movies of this type you can’t possibly enjoy them. Just accept that the lightsaber works.
My response: This isn't about thought or long-term scrutiny, it's about split-second response. My instant reaction was confusion. The weapon wouldn’t be useful. Wielding a lightsaber (or fighting with a cardboard wrapping paper tube, the personal experience from which I draw my conclusion) requires the wrist to pivot and twist. Imagine any sword with a hilt. Even with more controlled wrist action, any movement potentially could include incidental wrist and forearm contact with the hilt. A sword where contact with the hilt could slice off your own hand is a design flaw. It could be argued that the flaw exists in the Star Wars universe, and not the filmmakers’ workshop. But, I disagree. To think that crosses a line. When we have to apply conscious reason to a story element on behalf of the storytellers' shortcomings it’s a breach of contract with the audience, making us less likely to suspend disbelief.
The "X-Wing" DefenseThe argument: Why do the X-Wings open their wings up for battle, effectively increasing their surface area, and therefore the chance that they can be hit? There’s not a lot of logic in that!
My response: Very few, if any of us, bring to the viewing of a Star Wars film the knowledge of space travel physics, so real world logic isn’t the point here. The real reason the X-Wing “attack position” exists is for dramatic effect. In A New Hope, just before the attack on the Death Star, the line, “Lock X-foils in attack position!” comes as a final moment of preparation. We know that everything the rebels have done to prepare for this moment has been done. When the wings lock into attack position we know the rebels are committed (locked in, if you will) to the assault on the Death Star. There’s no turning back now. It’s do or die. That it’s cool is incidental to the fact that it creates a final beat of dramatized preparation.
For you physics nerds, the logic of the X-Wing “attack position” can quickly be interpreted as More Wings = Greater Handling. Whether that is sound science or not doesn't matter because we're already on board with the idea.
The "It’s Just a Movie!" RationalizationThe argument: This is a movie about aliens, and space, and swords made of glowing plasma -- not to mention a mystical Force that binds the universe -- so what does it matter if something is illogical?
My response: This is like saying to the filmmakers, “I don’t care what you put on the screen as long as it looks cool and makes fun noises that I can replicate by pushing buttons on the officially licensed Star Wars Episode VII keychain.” This argument is made by people that think Suspension of Disbelief is a conscious decision on the part of the audience. It isn’t. It’s an unconscious effect of being told a story so engrossing that we are willing to toss away reality as we know it (see also: my defense of the X-Wing above). It’s a facet of storytelling, not coolness. To engage an audience in the fantasy genre you'd better stick to the rules that have been established in the story world.
Here are two examples: In Jaws we believe that shooting the tank in the shark’s mouth kills the shark because we want to believe Chief Brody will win. In Return of the Jedi we believe the Emperor can shoot lightning from his hands because we have accepted how evil he is, and through that, believe he is capable of powers we had not yet seen.*
The "Jabba's Sail Barge" PostulateThe argument: The sails atop Jabba's luxury barge are actual sails -- and isn't that pretty stupid?
My response: Actually, this kind of proves my point. I didn't recognize them as sails. That they're intended to be sails is irrelevant since they resonated with me, the audience, as bimini tops on a boat. I figured they were there to shade the passengers on the top deck. Seemed logical to me. That it was able to float across the desert I attributed to the technology available in the Star Wars universe.
The "Maybe You Don’t Like Star Wars Anymore" RebuttalThe argument: Maybe these movies aren’t for you.
My response: They probably aren’t. But, ANY film that works against its own credibility isn't for me. Let’s go back to the ships that populate the Star Wars universe. It doesn’t take a degree in Physics to understand that a ship like the Millenium Falcon wouldn’t actually fly. It’s clunky and it doesn’t look like anything that flies in our own world. So, right away, the storytellers have a bridge to cross in selling the idea. But we see the Falcon take off vertically, a rear thruster propelling it forward, and down-bursts of air as it comes in for a landing. We accept its credibility because we see enough “logic” in how it works. That it doesn’t physically resemble any flying vehicle in our own world, yet still flies, we chalk up to the unknown technology of the Star Wars universe. Boom. Suspension of Disbelief.
Why, then, is a lightsaber with a lightsaber hilt different? Because we’ve all pretended to fight with lightsabers. There is a physicality to it we can recreate in real life. We know what happens when the lightsaber (read: cardboard tube) hits us or our friend in the hand, arm, or leg: those limbs are no longer useful for the remainder of the fight because they've been lopped off. This rule became well-established in our minds as soon as Vader chopped off Luke’s hand in Episode V. The Episode VII lightsaber doesn’t hold up to the “logic” we bring to the table, nor does it hold up to the technology that’s been established across six prior Star Wars films. This design asks that we not only suspend belief, but that we suspend common sense.
*Also, we need to see the Emperor wield new a power because this is Luke’s final test. We need it to be more powerful than anything we’ve seen so that Luke’s victory doesn’t feel like cheating. Another lightsaber duel wouldn’t have cut it.