Why don't we see more dual-phase lightsabers?

Question

Dual-phase lightsabers are lightsabers that can be extended at the push of a button and typically have a range of up to 3 meter. Since the weight of a lightsaber is almost entirely in the handle, this seems to me as an incredibly useful tool for lightsaber duels.

When lightsaber duels became less common, they naturally went out of fashion, since shorter lightsabers are more practical and just as useful against droids and blasters.

What I'm wondering about is: Is there a canon₁ explanation as to why dual-phase lightsabers didn't make a comeback when lightsaber duels became more common again? Especially among Jedi like Obi-Wan and Anakin and the Sith they faced.

Some possible reasons I can think of:

• Dual-phase lightsabers are not as useful as they seem.
• They require very specific training. (no one knows how to use them effectively anymore)
• They are exceedingly difficult/expensive to make (doubtful).

_{1: by canon, I mean originating from a source of the same level of credibility as the one that says dual-phase lightsabers exist.}

Answer 1

Okay, to build out an answer here, (along with some knowledge of melee combat), there are some things that need to be laid out first.

1: While lightsabers are weightless, they produce a gyroscopic effect...which means they resist changes in motion...so it takes force to get them moving, and then takes more force to stop them moving once they get going. This is generally cited as the reason why lightsabers are so dangerous to the user, and why Jedi are normally the only ones who use them. (Once you got them moving, it could be hard to get them to stop)

2: A longer blade produces more gyroscopic force, this is why the 'lightsaber shoto' was favored by some, because it could be moved more easily and quickly than a full length lightsaber.

As a result, this means that fighting with a dual-phase lightsaber would be the equivalent of swapping between a one handed longsword, and a greatsword at a moments notice...only worse, because a greatsword isn't twice the length of a longsword.

So, here's a breakdown of what happens when you flip the dual-phase switch to extend the blade: Your blade doubles in length...it also doubles its gyroscopic force, so if it is already moving, good luck stopping it. This has the potential to be extremely potent in combat, but would be hard to master, and limits flexibility of the fighting style. For example, you could start with the blade short, extend it to increase its 'momentum', then re-shorten it before you try to stop it. This would let you hit like a warhammer without having to start or stop the warhammer's motion.

Unfortunately, this also means that any time you want to change the direction of the blade (which happens a lot) you have to hit that toggle, and are limited by the switch delay of the blade changing length. A brief delay like that can cost you your life in a battle that high paced. This is further complicated by how a dual phase lightsaber could work. Corran Horn's dual-phase saber had its length switched by twisting the handle, this requires two hands and is more time consuming that flipping a switch.

As a result, while this makes the weapon potentially very powerful, and quite good at surprising your opponents, it would be very difficult to master. You would have to learn to fight with a weapon that could double or halve its functional momentum at a moment's notice...and it can be hard enough to work with weapons of different mass, even if they aren't spontaneously changing in your hands.

So, in summary, a dual-phase lightsaber could be a very powerful weapon, but very difficult to develop mastery over, and even more likely to maim you while you are figuring it out. All of this together is why Luke dubbed dual-phase lightsabers 'something of a fad' for Jedi, and Master Skarch Vaunk dismissed them as 'only good for surprising an opponent.' In short, it seems that they were simply considered more trouble than they are worth.

Answer 2

If you forget the problem with the momentum and conservation of movement, there is still a big, big problem...

The leverage effect.

If your oponent block your blade with his, he can push his saber near the end of yours and multiply the force you have to withstand to.

And remember, you can't use your hand to help push, you have to apply the pressure only with your wrist...

Answer 3

I would think the dualphase lightsaber is pretty much only useful for a one time trick and then you better hope it lands a hit.

There really isn't much more convenience in it. Although making the blade longer for meleeing with a bunch of droids seems like it would be rather useful.

Also now that i think about it, another reason for not having a dual phase would be something like:
And this is just basically so you can picture what i am talking about. 3 meters is roughly 9 feet. 1.3 is about 4 feet. So if i swing a 9 foot pole at you and you block it somewhere in the middle, then i would either have much farther to have to draw my sword back to get out of your block or i would have to take time to make the blade smaller so i could move it into a blocking position for a counter strike.

I think something like that!