The Empire Strikes Back is set three years after the Death Star has been destroyed. During this time, the Rebel Alliance has been forced out of Yavin IV by the Galactic Empire. Princess Leia, together with Han Solo and Luke Skywalker, establishes a new base on the icy planet Hoth. On the other hand, the Imperial Fleet that is led by Darth Vader searches for the location of their new base.
As he investigates a potential meteor strike, a wampa kidnaps Luke. He escapes from its lair using his lightsaber but he soon starts to lose his strength due to extreme coldness of the environment. An apparition of Obi-Wan Kenobi tells him to head for Dagobah and there, he must train under the command of the Jedi Master Yoda. Not long after, Han finds him and brings him back to the base.
While patrolling the vicinities, Han and Chewbacca discover a probe droid sent by the Imperial Fleet posing as an asteroid. Upon learning the Rebels’ new location, the Empire attacks the base using AT-AT Walkers. Han and Leia flee with C3PO and Chewbacca using the Millenium Falcon but their vessel malfunctions. They decide to hide in an asteroid belt while Darth Vader calls for bounty hunters to them. At the same time, Luke gets on board an X-wing fighter with R2-D2 and uses it escape. They crash land on planet Dagobah. There he meets Yoda who has some doubts before accepting him as his pupil.
After their escape, Han decides that they should go to Cloud City, a floating gas mining colony located in Bespin. It is headed by a close friend of his, Lando Calrissian. Little they do know that one of the bounty hunters, Boba Fett, has already tracked down the Millenium Falcon. Upon their arrival, they walk straight into a trap and Lando brings them before Darth Vader. Darth Vader intends to use his captives as bait to flush out Luke from wherever he is hiding. An omen reveals Han and Leia’s capture to Luke and though Yoda tries to dissuade him, he sets out to save them.
Darth Vader breaks the deal he made with Lando and he snatches Leia from him. He wants to preserve Luke using carbon freezing and he tries the process on Han. He gives the now frozen Han to Fett who plans on handing Han over to Jabba the Hut and to claim the bounty for him. Because he was just forced by the Empire to do their bidding, Lando helps Leia and the others to escape. The group then tries to save Han but Fett has already left for Tattooine.
Luke finally arrives and is surprised by Darth Vader. The two men fight with their lightsabers. Luke finds out that he’s no match for Darth Vader when he cuts off his right hand. Darth Vader urges Luke to join him in betraying the Emperor but Luke refuses. At that moment, Darth Vader tells Luke that he is his real father. Utterly shocked by this revelation, Luke falls through the air shaft. As he falls to the floating city, he emits a telepathic transmission to Leia. Leia receives it and she convinces Lando to rescue him. After saving him, R2-D2 fixes the hyperdrive of Falcon and they use it to escape the Imperial Fleet.
The group finds a medical frigate owned by the Rebels and there, Luke’s severed hand is replaced by a robotic hand. The movie ends with Lando and Chewbacca going on a quest to save Han from Jabba the Hut while Luke and Leia, together with R2-D2 and C3PO, wait for them to make contact.