Though Emperor Palpatine was the overarching villain of the original Star Wars trilogy, Darth Vader was a far more prominent antagonist. While Palpatine remained in his throne room, Vader was the Emperor's Fist, menacing the heroes at every turn. He proved to be one of the most important characters in the trilogy and the entire Skywalker saga. However, he nearly met his end in the first film. During the Battle of Yavin at the end of Star Wars: Episode IV - A New Hope, Darth Vader used his TIE Advanced to pursue the Rebel starfighters through the Death Star trench. He and his two wingmen shot down several members of Gold Squadron and Red Squadron before they could fire on the Death Star's exhaust port. Before long, Luke Skywalker was the only Rebel left in the trench, with Vader and the other TIE fighters in hot pursuit.

At one point, Vader was locked onto Luke's X-Wing, even taunting, "I have you now." But just as he began to open fire, Han Solo and Chewbacca arrived in the Millennium Falcon to save the day. The Millennium Falcon destroyed one of Vader's wingmen, and the other panicked. He veered into Vader's TIE Advanced, sending it tumbling into space. This bought Luke enough time to fire his ion torpedoes and destroy the Death Star. Vader was lucky enough to escape unscathed, but this was a close brush with death. If Chewbacca's aim had been slightly different or the collision between Vader and his wingman had been more explosive, the Sith Lord easily could have perished above the moon of Yavin 4. Such a thing seems like it would have been beneficial to the Rebellion's cause, but it might have spelled the galaxy's doom. So what would have happened after the Death Star's destruction if Palpatine's most powerful minion had died along with it?

The Emperor Saw Darth Vader as a Useful Tool -- But an Expendable One

First and foremost, Palpatine would have needed a new Sith Apprentice, or at least a new enforcer to do his dirty work. If Vader had died earlier in the timeline, the Grand Inquisitor would have been his most logical replacement, but the Inquisitors were no more by the time of A New Hope, so Palpatine would have needed to look elsewhere. The 2015 Darth Vader comic book series introduced some potential candidates. An Imperial doctor by the name of Cylo created a group of cyborgs whom he referred to as Vader's replacements. Among them were the Astarte twins, Tulon Voidgazer, Karbin, and an unnamed Trandoshan warrior. Cylo gave them cybernetic implants that, among other things, allowed them to mimic the effects of the Force. Displeased with Vader's failure to prevent the Death Star's destruction, Palpatine forces his apprentice to compete with Cylo's cyborgs to prove his worth. Each of these cyborgs eventually died at the hands of Vader or one another, but if Vader had not survived the Battle of Yavin, one of them -- most likely Morit Astarte, who was the last cyborg standing in the comics -- could have replaced him.

In the 2020 Darth Vader comic series, Palpatine discussed a different possibility. The hidden planet of Exegol, which first appeared in Star Wars: Episode IX - The Rise of Skywalker, was home to the Sith Eternal cultists as well as monstrous clones called Tankers. In Darth Vader #11, Palpatine told Vader, "They could be [Sith] should you fall... Any one of these might replace you." Palpatine was primarily playing mind games with Vader in this scene, but there could have been some truth in his words. It ultimately matters little who would have replaced Vader as the Emperor's Fist, because if Palpatine had his way, his new enforcer would not have held that position for long. Palpatine saw great potential in Luke and wanted to turn him to the Dark Side. Thus, Vader's demise would not have changed much about Palpatine's grand scheme. He still would have ordered the construction of a second Death Star and attempted to lure the Rebels into a trap on Endor or a similar location.

Darth Vader Was Responsible for the Battle of Hoth

In the short term, the Rebels would have benefited greatly from Vader's absence. For example, they could have maintained the secrecy of Echo Base on the planet Hoth, at least for a while longer than they did in canon. In Star Wars: Episode V - The Empire Strikes Back, an Imperial probe droid discovered evidence of a settlement on Hoth and transmitted it back to Vader's flagship, the Executor. Admiral Ozzel told his subordinates to ignore this, as he did not want to waste resources on an expedition to Hoth unless there was definitive proof of Rebel activity, but Vader overruled him: "That's it. The Rebels are there... That is the system, and I'm sure Skywalker is with them. Set your course for the Hoth system. General Veers, prepare your men." If not for Vader, the Empire would have seen no need to investigate Hoth, and Echo Base could have remained a major Rebel stronghold. The Rebels suffered heavy losses during the Battle of Hoth in The Empire Strikes Back, so if it had never occurred, their numbers would have been greater in future conflicts, such as the Battle of Endor.

According to the reference book Star Wars: Battles That Changed the Galaxy, there were over 3,250 Rebel casualties during the Battle of Hoth, compared to roughly 500 Imperial casualties.

Likewise, Luke would have had more time to train with Yoda on Dagobah. In The Empire Strikes Back, Luke had to leave before he had mastered his Jedi skills because he sensed that Han and Leia Organa were in danger, having been captured by Imperial forces in Cloud City. However, this would not have been the case if Vader had died during the Battle of Yavin. Without the Battle of Hoth, Han could have waited to leave the planet until the Millennium Falcon was fully repaired, avoiding the need to stop by Cloud City. Even if he and Leia had gone to Cloud City for some other reason, Vader would not have been there to spring a trap for them as he did in The Empire Strikes Back. Yoda passed away in 4 ABY, so Luke only would have had one additional year to learn from the Jedi Grandmaster, but that still would have been significant. Vader's death during the Battle of Yavin also would have prevented the iconic scene of Luke learning that he was Vader's son. Obi-Wan's Force ghost probably would not have told him, as in the films, he kept it secret until Luke directly questioned him about it. Throughout this alternate version of Star Wars: Episode VI - Return of the Jedi, Luke still would have believed that his father was a heroic Jedi who had been slain by Vader.

Darth Vader Was Key to the Empire's Downfall

Towards the end of Return of the Jedi, the negative consequences of Vader's death would have become apparent. In the film, Luke came dangerously close to falling to the Dark Side, as evidenced by his ferocity during his duel with Vader on the second Death Star. As Palpatine said, Luke's hate made him more powerful. However, after severing Vader's cybernetic hand, Luke had a moment of clarity that cut through his anger. He believed that Anakin Skywalker still existed deep beneath Vader's mechanical shell and that it was not too late for him to redeem himself. He cast his lightsaber aside and declared, "I'll never turn to the Dark Side... I am a Jedi, like my father before me." Luke's love for his father prevented him from succumbing to his negative emotions, so if Vader had not been present, Palpatine likely would have been able to manipulate Luke just as he had manipulated Anakin all those years ago. He might have taken this opportunity to reveal to Luke that he was the son of Vader, further stoking his rage and confusion.

Even if Luke was able to resist the Dark Side's temptation, his chances of winning a one-on-one duel against Palpatine would have been extremely slim. Even with an extra year of training from Yoda, he would have been a relatively new Jedi facing one of the most dangerous Sith Lords in history. In Return of the Jedi, Luke is powerless against Palpatine's Force lightning; he only survives because Vader turned against his master and sacrificed himself to defeat Palpatine. That would have been impossible if Vader had died during the Battle of Yavin. Had Luke failed to defeat Palpatine, one of two scenarios would have occurred, neither of them good. The less devastating possibility is that the Rebels would have destroyed the second Death Star while Luke was still within it. This would have led to the downfall of the Empire just as it did in canon, but it would have robbed the galaxy of one of its greatest heroes. The worst option is that Luke would have joined forces with Palpatine and prolonged the Empire's reign of terror throughout the galaxy. This was one of George Lucas' early plans for Return of the Jedi's ending, leading to another series of Star Wars films in which the heroes would have needed to defeat Luke or bring him back to the Light Side. Despite the short-term benefits Vader's death during the Battle of Yavin would have brought, it was for the best that he survived the events of A New Hope.