Amid a galactic civil war, Rebel Alliance spies have stolen plans to the Galactic Empire's Death Star, a massive space station capable of destroying an entire planet. Imperial Senator Princess Leia of Alderaan, secretly one of the Rebellion's leaders, has obtained its schematics, but her starship is intercepted by an Imperial Star Destroyer under the command of the ruthless Darth Vader. Before she is captured, Leia hides the plans in the memory of astromech droid R2-D2, who flees in an escape pod to the desert planet Tatooine accompanied by protocol droid C-3PO.
The droids are captured by Jawa traders, who sell them to moisture farmers Owen and Beru Lars and their nephew Luke Skywalker. While cleaning R2-D2, Luke accidentally triggers part of a holographic recording of Leia, in which she requests help from Obi-Wan Kenobi. Later, after Luke finds R2-D2 missing, he is attacked by scavenging Sand People while searching for him, but is rescued by elderly hermit "Old Ben" Kenobi, an acquaintance of Luke's, who reveals that "Obi-Wan" is his true name. Obi-Wan tells Luke of his days as one of the Jedi Knights, the former peacekeepers of the Galactic Republic who drew mystical abilities from a metaphysical energy field known as "the Force", but were ultimately hunted to near-extinction by the Empire. Luke learns that his father fought alongside Obi-Wan as a Jedi Knight during the Clone Wars until Vader, Obi-Wan's former pupil, turned to the dark side of the Force and murdered him. Obi-Wan presents Luke with his father's old lightsaber, the signature weapon of Jedi Knights.
R2-D2 plays Leia's full message, in which she begs Obi-Wan to take the Death Star plans to her home planet of Alderaan and give them to her father, a fellow veteran, for analysis. Although Luke initially declines Obi-Wan's offer to accompany him to Alderaan and learn the ways of the Force, he is left with no choice after discovering that Imperial stormtroopers have killed his aunt and uncle and destroyed their farm in their search for the droids. Traveling to a cantina in Mos Eisley to search for transport, Luke and Obi-Wan hire Han Solo, a smuggler with a price on his head due to his debt to local mobster Jabba the Hutt. Pursued by stormtroopers, Obi-Wan, Luke, R2-D2 and C-3PO flee Tatooine with Han and his Wookiee co-pilot Chewbacca on their ship the Millennium Falcon. As they reach the planet's orbit, two Star Destroyers try to intercept them, but Han is able to jump to hyperspace by reaching lightspeed.
Before the Falcon can reach Alderaan, Death Star commander Grand Moff Tarkin interrogates Leia about the location of the Rebels's secret base, with the threat of destroying her home planet, and, when she answers that the base is on Dantooine, he orders Alderaan destroyed simply as a show of force. As the group arrives in the asteroid field that now stands in place of Alderaan, Han spots an Imperial TIE fighter and is taunted into chasing it and shooting it down, allowing the Falcon to be captured by the space station's tractor beam. Inside the Death Star, Obi-Wan attempts to disable the tractor beam, and Luke persuades Han and Chewbacca to help him rescue Leia after discovering that she is scheduled to be executed. After disabling the tractor beam, Obi-Wan sacrifices his life in a lightsaber duel with Vader, allowing the rest of the group to escape the Death Star with Leia. Using a tracking device, the Empire tracks the Falcon to the hidden Rebel base, actually located on Yavin IV.
Leia's schematics reveal a hidden weakness in the Death Star's thermal exhaust port, which could allow the Rebels to trigger a chain reaction in its main reactor with a precise torpedo strike. While Han abandons the Rebels after collecting his reward for rescuing Leia, Luke joins their starfighter squadron in a desperate attack against the approaching Death Star. In the ensuing battle, the Rebels suffer heavy losses as Vader leads a squadron of TIE fighters against them, but Han unexpectedly returns to aid them in the Falcon, narrowly managing to save Luke before Vader can shoot him down. Guided by the disembodied voice of Obi-Wan's spirit, Luke turns off his targeting computer and uses the Force to guide his torpedoes into the exhaust port, destroying the Death Star moments before it fires on the Rebel base. In a triumphant ceremony at the base, Leia awards Luke and Han medals for their heroism.
Mark Hamill as Luke Skywalker
Harrison Ford as Han Solo
Carrie Fisher as Princess Leia
Peter Cushing as Grand Moff Tarkin
Alec Guinness as Obi-Wan Kenobi
Anthony Daniels as C-3PO
Kenny Baker as R2-D2
Peter Mayhew as Chewbacca "Chewie"
David Prowse as Darth Vader
James Earl Jones as the voice of Darth Vader.
Other actors include Phil Brown and Shelagh Fraser as Luke's Uncle Owen and Aunt Beru; Jack Purvis, Kenny Baker's partner in his London comedy act, as the Chief Jawa in the film; and Eddie Byrne as Vanden Willard, a Rebel general. Denis Lawson and Garrick Hagon played rebel pilots Wedge Antilles and Biggs Darklighter (Luke's childhood friend), respectively. Don Henderson and Leslie Schofield appear as Imperial Generals Cassio Tagge and Moradmin Bast, respectively, and Richard LeParmentier plays Admiral Motti. Alex McCrindle portrays General Jan Dodonna, Alfie Curtis portrays Dr. Evazan and Peter Geddis portrays Captain Raymus Antilles. Michael Leader plays a minor role as a Stormtrooper known for accidentally hitting his helmet against a door. Heavily synthesised audio recordings of John Wayne from earlier films were used as the voice of the Imperial spy Garindan.
the first installment of the original Star Wars trilogy and the fourth episode of the "Skywalker saga".
Originally caled Star Wars and retroactively titled Star Wars: Episode IV – A New Hope
the first of the Star Wars franchise to be produced.