Duel on Cloud City After failing to capture Luke Skywalker during the Battle of Hoth , Darth Vader — Skywalker ' s father — set a trap for Skywalker on the Cloud City of Bespin . He captured Han Solo and Leia Organa to torture them , hoping to lure Skywalker out of hiding . Skywalker saw a vision of his friends ' suffering while on Dagobah , where he trained with Jedi Master Yoda , and rushed to Cloud City to help them . When he arrived , Skywalker briefly encountered Imperial troops and Boba Fett , who was taking a carbon - frozen Solo to his ship . Skywalker avoided the enemy forces and made his way to the carbon - freezing chamber and found Vader waiting for him , and the two engaged in a lightsaber duel throughout the chamber . The duel progressed through the city ' s processing vane and onto a maintenance catwalk where Vader disarmed Skywalker by slicing off his weapon hand . He then tempted the young Jedi apprentice to join him and embrace the dark side . When Luke refused , Vader revealed that he was the boy ' s own father , Anakin Skywalker . Rather than allow himself to be captured , Skywalker threw himself off the platform where they had fought , before landing and hanging helplessly at the bottom of the city . Skywalker was rescued by Organa , Chewbacca , and Lando Calrissian in the " Millennium Falcon " before returning to the Rebel fleet , where they began plotting a mission to rescue Solo from Jabba the Hutt on Tatooine . Prelude . A few days prior to the duel , the Alliance to Restore the Republic had been dealt a disastrous defeat in the Battle of Hoth . Though the Alliance had managed to stave off total destruction , the conflict had seen the Alliance ' s new headquarters destroyed and had scattered their surviving forces . As the Imperial assault had neared completion , Han Solo , Leia Organa , Chewbacca , and C - 3PO managed to escape off - world in Solo ' s personal ship , the " Millennium Falcon " . However , the " Falcon " had been undergoing extensive repairs prior to the battle , and , unknown to its crew , its hyperdrive motivator was damaged to the point of being non - functional . Vader , who had led the Imperial assault , had been attempting for months to track down and capture Luke Skywalker with the intent of making the boy his apprentice . He arrived in the hangar where the " Falcon " had been docked just in time to see the ship leave and , recognizing it , he concocted a plan to capture it and its crew . Vader hoped that if he could capture and torture Skywalker ' s friends , the young Jedi would feel their pain through the Force and attempt to rescue them . To that end , he sent part of his personal armada , Death Squadron , to capture the " Falcon " . Solo managed to evade the pursuers , but he soon came to realize that the damage to the " Falcon ' s " hyperdrive was so extensive that he could not repair it without assistance . Unable to meet up with the remains of the Rebel fleet , Solo attempted to seek refuge on the nearby planet of Bespin . An old friend of Solo ' s , Lando Calrissian , had become Baron Administrator to Bespin ' s largest settlement , Cloud City , and Solo believed Calrissian could help him repair the " Falcon " . However , the bounty hunter Boba Fett had informed Darth Vader of Solo ' s destination , and , with the advantage of functioning hyperdrives , an Imperial detachment under the Dark Lord ' s command arrived at Bespin before Solo ' s crew . After Vader arrived Cloud City , he informed Calrissian of his plan to use Solo and his friends to capture Skywalker . In return for his cooperation , Vader promised that the Empire would leave Cloud City to its own affairs after Skywalker had been captured . With the threat of Imperial occupation looming over his head , Calrissian was forced to comply . With his cooperation , Vader captured Solo and his companions shortly after they landed . He then began torturing the Rebels to lure out Skywalker . The plan was successful ; Skywalker sensed his friends ' anguish on Dagobah , and prepared to go to Bespin to save them . In doing so , he disregarded the advice and pleas of his masters , Yoda and Obi - Wan Kenobi , the latter of whom told Skywalker that his friends ' suffering was almost certainly part of a trap . Luke approached the Cloud City in his X - wing starfighter , unaware that the Imperial forces occupying the city had been tracking his progress since his arrival in orbit . He landed his craft without incident , and proceeded cautiously into the city . As he and R2 - D2 began the search for his friends , he encountered Boba Fett and a group of Imperials who were transporting Solo — encased in carbonite — to Fett ' s ship . Skywalker , hoping not to reveal his presence , quietly followed the group for a short time until they disappeared from sight . As Skywalker prepared to continue through the city , Fett suddenly reappeared and fired on Skywalker , who ducked around a corner to avoid the shots . After firing a few deterring blaster bolts , Fett disengaged and Skywalker , not knowing what Fett ' s cargo had been , did not attempt to follow him . Shortly after , he encountered Organa and Chewbacca , who were being brought to Vader ' s flagship as prisoners . The stormtroopers escorting the pair began shooting at Skywalker , who took cover again . Organa saw him and , aware of Vader ' s trap , desperately tried to break free of the grip of an Imperial officer in an attempt to warn Skywalker . As the group of Imperials with Organa broke off the fight and dragged her away , Luke attempted to follow . Just as he passed through the door where Organa had disappeared , it slammed shut behind him , cutting him off from R2 - D2 . Making his way through the catwalks and elevators of a gas - processing vane in the lower levels of Cloud City , he eventually reached the dimly lit carbon - freeze chamber . Suddenly , the chamber lit up , revealing Darth Vader , standing atop a flight of steps to the walkway above . Vader claimed that while the Force was with Luke , the boy was not a Jedi yet . Striding up to the Dark Lord , Skywalker ignited his lightsaber . Vader responded by calmly activating his own saber , and the duel began . The duel . Skywalker opened the duel with two brief , unsuccessful strikes at Vader ' s torso . He then attempted an overhand strike but the Sith Lord blocked the attack with a one - handed grip on his weapon . Skywalker ' s assault resulted in a blade - lock , which Vader broke by casually pushing Skywalker to the ground . Skywalker quickly recovered and advanced , engaging in an aggressive string of attacks as Vader retreated . However , Vader soon counter - attacked and forced Luke back to the head of the stairs . During a subsequent pause in the duel , Vader complimented Skywalker on his swordsmanship , and Luke arrogantly agreed . As he spoke , Skywalker attacked Vader again , but after a few strikes Vader disarmed him with a quick flourish . Vader then lazily slashed at Skywalker , hoping to herd him towards the carbon freezing pit . Skywalker dove out of the way of the attack and rolled down the stairs to the freezing chamber ' s main platform . Vader jumped after Skywalker and held him at blade - point just beyond the edge of the pit . As the pit was closed and Skywalker ' s attention was focused on his opponent , the young Jedi did not perceive Vader ' s trap . Vader then claimed that Skywalker ' s destiny lay with him , and that Obi - Wan had known it . As Skywalker denied this , Vader continued to walk Luke towards the now - open freezing pit and Luke , not realizing that the pit had opened ( or indeed that it was even there ) , continued to retreat . As such , when Vader performed another casual swing of his weapon , Skywalker backed right over the lip of the pit and fell in . Vader immediately activated the chamber with the Force , remarking that his victory had been disappointingly easy . But before the freezing process could begin , Skywalker used the Force to leap out of the pit and grab onto the hoses above it . Vader then approached the pit , contemptuously musing that Skywalker was not as strong as he had been told , when he heard a metallic crash from above and noticed Skywalker trying to climb the tubing above the pit . Complimenting Skywalker ' s escape , Vader slashed one of the hoses in an attempt to dislodge his opponent , triggering alarms that started blaring through the chamber . Skywalker jumped down , grabbed the severed hose , and used it to spray gas into Vader ' s masked face . With the Sith Lord momentarily stunned , Skywalker used the Force to summon his lightsaber to his hand . He re - engaged Vader and locked blades with him again . Vader taunted Skywalker , asserting that , while he had control of his fear , unleashing his anger was the only path to victory . The Sith Lord broke the blade - lock and attacked . Skywalker managed to fend off Vader ' s onslaught , flipping over the Sith Lord to avoid an attack at his legs . Landing behind Vader , Skywalker went on the offensive and drove the Sith Lord to the edge of the platform , kicking Vader in the abdomen . Vader toppled over the edge of the platform and disappeared from sight . Seeming to have gained the upper hand , Skywalker jumped down after Vader . Searching for the Sith Lord , Skywalker wandered through a tunnel into the city ' s processing vane , which overlooked a deep , low - pressure reactor shaft . There , he encountered Vader , standing with his weapon ignited at the far end of the chamber . As Luke began to haltingly advance on his opponent , Vader telekinetically tore a fixture of metal pipes off of a wall behind Skywalker and threw it at him . As Skywalker turned and cut the fixture apart , the Sith Lord lunged , engaging Skywalker in a brief bout of swordplay . As the pair locked blades , Vader used the Force to throw a metal box at Skywalker , which smashed into the back of his head and broke the blade - lock . Vader then pulled back and began telekinetically pummeling Skywalker with various objects in the room . As Skywalker failed to hold off the improvised missiles , a misdirected piece of piping smashed through a large observation port behind him . The chamber immediately and violently depressurized , sucking Skywalker out into the reactor shaft while Vader grabbed a nearby wall for support . As the pressure equalized , Vader went to the shattered observation port and observed that Skywalker had managed to grab the railing of a catwalk several floors below . Skywalker climbed up onto the catwalk and again began searching for Vader . Eventually , he entered a narrow corridor in the processing vane , where he was ambushed by Vader . The Sith Lord engaged in a ferocious series of overhanded strikes , which forced Skywalker onto the defensive . Overwhelmed by Vader ' s strength , Skywalker was rapidly driven back through the corridor . Blade - locking with the boy , Vader threw him against a wall and slashed at him , but Skywalker recovered just in time to avoid Vader ' s attack . The attack struck the wall behind Skywalker and showered the corridor in sparks . After dodging another such attack , Skywalker attempted to retreat along the catwalk from whence he had come but Vader quickly cut him off . Shoving Skywalker onto the dead - end that was the central catwalk , Vader continued his relentless assault . Blocking or shunting aside everything Skywalker threw at him , Vader soon blade - locked with the youth one final time and pushed him to the ground . Putting his saber at Skywalker ' s throat , Vader proclaimed the boy defeated , and told him that further resistance would end in Skywalker sharing Kenobi ' s fate . But Skywalker defiantly drove Vader ' s weapon aside and regained his feet . As they renewed their fight , Skywalker managed to slightly wound Vader ' s right shoulder with a desperate swing before retreating . Enraged by the breach in his defenses , Vader moved to end the duel , driving Skywalker to a small extension at the end of the catwalk . There , Vader sliced apart a piece of equipment on the catwalk , parried Luke ' s weapon hard enough to expose his wrist , and sliced off his right hand with a swift undercut . Both Luke ' s hand and his lightsaber fell into the depths of the reactor shaft . Revelation and escape . As Skywalker recoiled with a scream of pain , Vader deactivated his weapon and began conversing with Skywalker . While Skywalker retreated to the end of the extension , Vader attempted to sway him to the dark side , promising him that the two of them could end the Galactic Civil War and bring order to the galaxy . Skywalker refused , but Vader then revealed to him that he had formerly been Anakin Skywalker , Luke ' s own father . Though Skywalker vehemently denied the claim , as Kenobi had told him that Vader had betrayed and murdered Anakin , he sensed that Vader was telling the truth . Though shocked and horrified , Skywalker found the courage to jump off the catwalk to seemingly certain death rather than join the Empire . As he fell , Skywalker was sucked through a number of vents , which eventually deposited him on a vane below Cloud City . Badly injured , exhausted and mentally spent , he called out to Kenobi for aid but received no reply . He then desperately attempted to contact Organa through the Force . Unbeknownst to Skywalker , Lando Calrissian had switched allegiances to the Rebels in response to Vader changing the terms of their agreement several times . Realizing that Vader could not be trusted to keep his word , Calrissian had freed Leia and Chewbacca and they attempted to retrieve Solo from Fett . Although they failed to do so , they had managed to reach the " Falcon " and escape the city . While on their way to leave Bespin , Organa heard Skywalker ' s mental cry for help and ordered the freighter around to rescue him . As the crew of the " Falcon " recovered Skywalker , Vader arrived at his flagship , the " Executor " , and pursued the freighter . As the " Falcon " left Bespin ' s orbit , the crew attempted to jump to hyperspace , only for the hyperdrive to fail once again . As the " Executor " closed in , panic set in on the " Falcon " as the rebels desperately attempted to discover what was wrong with the supposedly repaired hyperdrive . As the freighter evaded a small group of TIE fighters , Vader telepathically contacted Skywalker and attempted once more to turn him to the dark side . Skywalker continued to struggle with Vader ' s revelation , particularly with the fact that Kenobi had failed to tell him the truth . With the rebels unable to figure out why the hyperdrive of the " Falcon " was not functional , the " Executor " closed and prepared to tractor the freighter . However , R2 - D2 had discovered during the escape from Cloud City that the Falcon ' s hyperdrive had in fact been repaired , and that Imperial agents had simply deactivated it . The astromech droid quickly reactivated the drive , and the " Falcon " lurched into hyperspace just before the Imperials could activate the tractor beam . Aftermath . Despite Vader ' s tendency to execute Imperial officers who had failed him on the spot , Vader spared Admiral Firmus Piett , the CO of the " Executor " , and strode from the bridge in silence . Meanwhile , the " Falcon " rendezvoused with the Rebel fleet , where Luke was fitted with a prosthetic hand that was visibly indistinguishable from his original one ( he would later construct a new lightsaber to replace his lost weapon as well ) . As his operation was concluded , Calrissian and Chewbacca left aboard the " Falcon " for Tatooine with the intent of locating Solo in order to free him . Vader ' s revelation haunted Skywalker , shaking his faith in Kenobi and destroying the image of the father he had thought he had and looked up to . However a year later he had managed to come to terms with his parentage , and even thought to use it to convince Vader to return to the light . During his confrontation with Vader and the Emperor on the second Death Star during the Battle of Endor , he managed to do just that . Redeeming himself , Vader killed the Emperor and died from his wounds , bringing balance to the Force . Behind the scenes . The duel between Darth Vader and Luke Skywalker in " " is regarded by many " Star Wars " fans as the most memorable lightsaber duel in " Star Wars " history . As George Lucas wanted the lightsaber fights to gradually become " faster and more intense " as Skywalker became better at using a lightsaber , a shift in dueling style became evident , with some one - handed fighting forms making their first appearance — a peek at what lightsaber duels of olden times would eventually be revealed to look like . The revelation of Skywalker ' s parentage was kept so secret that even David Prowse , the actor playing the body of Darth Vader and speaking the lines on set , did not know the truth . Instead , he spoke the line " Obi - Wan killed your father " , which had been printed on a substituted page of the screenplay . Meanwhile , the overdubbed voice of James Earl Jones spoke the true line . Mark Hamill himself was only told moments before shooting the scene , and no one else on the cast other than Jones and Hamill found out until Episode V ' s premiere . In popular culture . The great lengths that the production staff went to prevent the identity of Skywalker ' s father from being leaked to the public was eventually spoofed in " The Simpsons " episode " Worst Episode Ever , " where one of the invaluable " Star Wars " memorabilia that Mrs . Prince was unwittingly selling to Comic Book Guy was a film reel labeled " Alternate Ending : Chewbacca is Luke ' s Father . "