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[Star Wars] What if Luke had gone to the Imperial Academy and never joined the Rebel Alliance?

Having never met Ben Kenobi and flown off to the Death Star with Han Solo, what would the shape of the Galaxy be?
gpt
Well, let's assume that Luke left for the Academy before any of the events in Episode IV take place. By the time the Tantive IV has escaped to Tatooine with the Death Star plans, the Skywalker homestead is home to only two people: Owen and Beru. After an unexpectedly fruitful moisture farming season, Owen's purchase of a few droids meant that Luke was no longer essential for keeping the homestead running, and with the blessing of his aunt and uncle, he left to join the Imperial Academy.

Let's start with the droids. For the beginning of their adventure on Tatooine, little changes. They escape in the pod, and both are eventually captured by the Jawas. Owen, still on the lookout for a decent translator and any other droids that might help out on the farm, purchases the both of them.

R2 coerces another droid owned by the Skywalkers to remove his restraining bolt, and flees into the desert, this time stealing the Skywalkers' family landspeeder in the escape. Without Luke maintaining it, the speeder breaks down early into the trip, but the little astromech droid finds its way to Obi-Wan's hermitage without further trouble. Seeing the importance of R2's mission, he agrees to ferry the droid to Alderaan, though has no plans to acquiesce Leia's request. He is a simple hermit now, not a man of war.

Without the landspeeder to sell, Obi-Wan has nothing but his own meager savings to pay for a flight, and must rely on merely the promises of wealth once the precious cargo is delivered. Han Solo, having spent too many years as a smuggler to accept a job that sounds too easy (and with no up-front pay, to boot) quickly declines Obi-Wan's offer. For a moment, as he walks away to seek a more weak-minded pilot, Obi-Wan feels a strange sense of loss, despite the brazen smuggler's seemingly simple and arrogant demeanor.

When Alderaan is destroyed, Obi-Wan collapses in the cargo hold of the rickety freighter he's "coerced" his way onto. Surrounded by cargo containers filled with the illegal exports of the Hutt lords, and the fate of the galaxy ever more uncertain, Obi-Wan has never felt more alone. Next to him, R2-D2 lets slip a mournful trill, and Obi-Wan agrees: Something far beyond either their control has gone wrong.

Before we go any further, let's consider the life of young Skywalker, new recruit to the Imperial Navy: With his massive Force Potential and previous experience flying on Tatooine, Luke quickly finds his way to the flight academy, and rises through the ranks at record speed. The training is rigorous, and to this date, he is yet to see real combat. While he is boisterous and enthusiastic like his peers, and his scores in the simulators are compared to the likes of Baron Fel, he does not find pleasure in death. Despite a number of runs against live targets, Skywalker consistently failed to make even a single kill.

Upon graduation, he is assigned to Black Squadron, one of the many TIE squadrons stationed on the Death Star. To his superiors, it's a punishment. The might of the Death Star is so apparent that none would be foolish enough to attack it with snubfighters, and there is little glory in patrol runs. To him, it is a relief.

When the alarm klaxons echoed through the halls announcing the escape of a dangerous prisoner, and the description of a strange old man and his rogue droid that assisted in the escape appeared on his datapad, he paid it little heed. When one of his fellow pilots shouted to the others in the barracks that he'd managed to obtain a live feed of the prisoners escaping, he reluctantly takes a look at the screen.

The starship, boxy and ugly, a stark contrast from the pristine hanger it was docked in, filled the screen. According to one of his fellow pilots, the smuggler who flew it in was blasted to bits upon the discovery of enough Ryll spice to make a sarlacc OD.

At the boarding ramp, a beautiful young woman fired wildly towards troopers offscreen. The ship's small blaster array assisted as well, melting the hangar elevator to prevent reinforcements.

When the camera feed switched to Vader, locked in combat with the strange old man, the hooting and hollering turn instantly to gasps of disbelief. Most of the pilots were aware of Vader's reputation, and a few who had passed him in the halls could even attest to the dark aura that followed him like a physical presence, but none believed the rumors that the Dark Lord carried a lightsaber like the Jedi of old, let alone one colored a deep, angry crimson.

Luke does not join them in their cheering. Since the destruction of Alderaan, his apprehension has grown by the day.

The fight has grown more intense. The old man holds his own, but is quickly, clearly faltering under Vader's sheer power. 

Amidst the cheers and whoops of his peers, Luke has a strange revelation: He doesn't want the old man to die.

They are standing on opposite sides of the open blast doors. Were they to close, the old man would be safe to escape to the young woman shouting at him from the starship.

He can see it happening in his minds eye: The blast doors slam shut, separating the old man from Vader.

All it would take is someone there to press the button on the console.

He wants *so badly* to be able to press that button, so much that he can almost feel the texture of it under his thumb, and in his mind he *presses*.

And the blast doors slam shut.

The man survives, and escapes to the ugly, boxy starship with the woman. To everyone's surprise, the tractor beams do not immediately stop their escape.

When Black Squadron is sent after them, they are ordered not to make a killing blow. The ship has a tracking device attached, and the location of the hidden Rebel base has priority over the capture of a few escaped fugitives.

That night, Luke falls asleep replaying the sight of the blast doors slamming shut in his head, unable to shake the thought that something far beyond his control has gone wrong.

Meanwhile, Obi-Wan has escaped the Death Star with the young princess in tow. Though this was not the trip to Alderaan he anticipated, none of that matters now. Sensing a trap, he urges Leia not to travel directly to the Rebel base, but she is insistent. The data stored in R2-D2 is far too valuable to risk delaying its delivery.

When they arrive in the Yavin system, there is little time to prepare a plan. The stolen starship's hyperdrive is fast, but nothing compared to the advanced systems in the imperial fleet. They arrive mere hours before the full might of the Empire. With the plans to the Death Star hastily analyzed, a plan is put into place.

The imperial fleets arrive.

The rebel squadrons launch.

The battle of Yavin IV has begun.

In the chaos of the battle, Vader is rushing to scramble a force against the rebel attack that none of his superiors suspected. He is forced to pick the one squadron at the ready: Black Squadron.

The battle rages, and both squadrons suffer heavy losses. Vader's own personal wingmen are killed, forcing them to be replaced by the more elite members of Black Squadron. On any other day it would have been an honor. Today, it was nothing short of terrifying.

The last few fighters in the Alliance fleet are approaching the end of the trench run, but Vader is picking off the remaining rebels with terrifying efficiency as they rush through the Death Star's docking ring. Soon there are only three. Then two. Then finally just one X-wing, its stabilizer shot to hell and back, leaking coolant, and her pilot shouting furiously on open channels.

Luke watches in slow motion as his fighter's display informs him that Vader's fighter has locked on to the final enemy fighter.

In that moment, he knows precisely what he has to do.

As Luke slams his TIE into the side of Vader's craft, Vader feels his son's final thoughts: not of anger, or desperate confusion, but of calm certainty. 

As the dark lord's TIE spins wildly away from the Death Star, it's stabilizers and propulsion rendered completely useless by the explosion, he does not shout in fury, nor does he act quickly to return his craft back to a stable vector. Instead, he feels only a strange sense of calm. Were he a wiser man, he might have identified the source of his peace: Pride.

Wedge Antillies makes the final shot that destroys the Death Star, and is hailed as a hero to the Rebellion, but the victory came at an incredible loss: of all the pilots of all the Alliance squadrons sent on their desperate mission, he was the sole survivor.

This day, there is great hope for the Rebellion. Obi-Wan, one of the greatest Jedi generals of the Old Republic and veteran of the Clone Wars, has joined the Alliance. Though reluctant to fight openly, he carries with him more than just his knowledge of the Force and expertise in war. He carries with the legacy of the Jedi, and the secret he's kept for more than 20 years: That a young woman, strong in the Force and a former senator of Alderaan, is much, much more than she seems.