The Story: Part of the reason a lot of people prefer TESB to "A New Hope" is the flowering of the characters, Irvin Kershner's rock-solid direction (the principles were never better in the series), and the more mature stance of this film—the stakes are higher, and our heroes get their noses bloodied a bit—which gave fans the illusion that the series was getting more sophisticated. *
Then there's Yoda. TESB serves two functions in The Original Trilogy (as opposed to the First...): to make things very bad for the rebels (including the revelation of one essential plot and character complication); as well as the introduction of the little green Jedi Master (voiced and operated by Muppet-master Frank Oz), who represents the last spark in the complicated (though still unspecified) Jedi back-story. He is the Creature By the Road who gives this Hero of a Thousand Faces the magic needed to defeat the Evil and complete his Quest. Yoda gives us a bit more insight (but only a bit) into the magic—the all-powerful "Force." As Luke had enough of the mysterious stuff to blow up the Death Star without his targetting computer, Yoda has some 'splainin' to do, a lot of exposition to put on his bony little shoulders.
Especially considering that...well...not to put too fine a point on it...he's a puppet.
The character, both exotic and familiar, bearing a passing resemblance to Einstein, became the "break-away" character of "The Empire Strikes Back" (Sorry, Lando!) and returned in every subsequent chapter of "Star Wars." And he's alien enough—small, vulnerable, big-eyed like a baby, yet paradoxically powerful—to appeal to all ages. His poetic "woo-woo" explanations of The Ways of the Force appealed to the more egg-headed of the fans, looking for a philosophy that offered power, so long as they didn't have to work to achieve it or do much to prove it. Yoda was a representation of their own neuroses, appearing to be weak, but secretly (and only in their dreams) powerful.
But they'd have to look past the fact that...ya know...he's a puppet?
The screen-caps expose that quite plainly; there isn't a lot of expression to the old boy, and the eyes look a bit glassy in some shots (because...they are!). But something happens when Frank Oz sticks his hand up Yoda and starts to wriggle the fingers inside his head. The pacing of the movements and the soulful way Oz applies them makes Yoda a very animate creature at 24 frames per second. You believe in the little guy. There is no disconnect between Yoda's words and body language, as they emanate from the same being and create a definable character audiences believe in.
Even though...like I said...he's a puppet!
And Yoda's writing's not bad, either. Lucas took the "crazy old man" persona that Alec Guinness rejected for Obi-Wan and mind-melded it onto the old Jedi, giving the creature a certain, temporary twee-ness, somewhere between an elf and a hobbit. With his backward sentence structure--he sounds like a writer for Time magazine back in the Luce days--and charged lines like "Luminous beings are we!" he is a one-man...er, one-being version of the first film's Mos Eisley Cantina sequence, satisfying both sci-fi and fantasy demands and grounding "The Force" in a stew of Zen and martial-arts disciplines. A hard task-master, he is. But audiences responded big-time to Yoda. Even when he stamped his little feet over Luke's lack of faith.
Oh, wait a minute! He doesn't have feet!
He's a freakin' puppet!
Which is why Industrial Light and Magic was sweating glycerin bullets before TESB premiered. A puppet? With so much dramatic weight to pull? Fortunately, Lucasfilm had out-sourced with the best--Oz of the Muppets as talent and consultant, and Stuart Freeborn, who'd done a lot of creatures for the first film, including Chewbacca. That Yoda was a puppet was undeniable but the illusion was carried off so well (not unlike the illusion of mechanical-man Darth Vader from the previous film) that audiences were charmed and bought it hook, line and little stinker. Yoda's success also probably emboldened Lucas to experiment with less thought-out and executed subsequent characters like the Ewoks, Howard the Duck, and Jar Jar, to audiences' everlasting regret.
Yoda, the Jedi Puppet-Master. One more example of how movies can sell an illusion.
The Set-Up: The Rebels have been routed from their temporary base on the ice-planet of Hoth. Our heroes split up: Han Solo (Harrison Ford), Chewbacca (Peter Mayhew) and C-3PO (Anthony Daniels) evacuate the Princess (Carrie Fisher), while Luke Skywalker (Mark Hamill) follows the spectral urgings of the late Obi-Wan Kenobi (Sir Alec Guinness) to seek out the Jedi Master, Yoda (Frank Oz), to train him. Luke and R2-D2 travel to the planet Dagobah, where the feeble Jedi Master puts Luke through rigorous paces.
Action, there must be!
(Yoda is perched on the feet of Luke Skywalker, who is doing a one-arm hand-stand near a marsh and telepathically stacking a stone atop another)
Yoda: Use the Force.
Yoda: Now, the stone.
Yoda: Feel it.
(Nearby, Skywalker's waterbound X-wing fighter sinks further in the bog and he loses his concentration, collapses, and causes Yoda, and the stones, to fall).
Skywalker: (Looking toward the water): Oh no.
Skywalker: We'll never get it out now.
Yoda: (Recovering): So certain are you.
Yoda: Always with you it cannot be done. Hear you nothing that I say?
Skywalker: Master, moving stones is one thing. This is totally different!
Yoda: No! No different! Only different in your mind.
Yoda: You must unlearn...what you have learned.
Skywalker: All right. I'll give it a try.
Yoda: No! Try not.
Yoda: Do. Or do not.
Yoda: There is no try.
(Skywalker concentrates and the fighter rises slowly...)
(...but his doubts in his ability take over and the ship sinks back into the water.)
Skywalker: (Out of breath): I can't. It's too big.
Yoda: Size matters not. Look at me.
Yoda: Judge me by my size, do you? Hm? And well you should not.
Yoda: For my ally is the Force. And a powerful ally it is.
Yoda: Life creates it. Makes it grow.
Yoda: It's energy surrounds us and binds us.
Yoda: Luminous beings are we...
Yoda (touches Skywalker's shoulder):...not this crude matter.
Yoda: You must feel the Force around you.
Yoda: Here, between you, me...
Yoda: the tree, the rock...
Yoda: Yes, even between the land and the ship.
Skywalker(walking away): You want the impossible.
(Alone by the water, Yoda shuts his eyes and raises Skywalker's fighter and sets it on land)
Skywalker: I don't...I don't believe it!
Yoda: That...is why you fail.
"Star Wars—Episode V: The Empire Strikes Back"
Words by George Lucas and Leigh Brackett and Lawrence Kasdan
Pictures by Peter Suschitzky and Irvin Kershner
"The Empire Strikes Back" is available on DVD from Fox Video
* It wasn't. Not to get too punny here, but there's a lot of empty space in TESB that wasn't there in "Stars Wars," aka "Chapter IV: A New Hope." Even looking at this scene, one can see all the padding and cross-cutting going on--and it's not to make way for John Williams' triumphant music--it's because TESB and Chapter VI: Return of the Jedi are underwritten and over-edited to the point that every character (even the robots) seems to earn a reaction shot to whatever insignificant thing happens.