When George Lucas made "Star Wars: A New Hope," there was no guarantee that it would inspire a saga of films that made break box office records. There were always plans to expand the "Star Wars" universe, and Lucas made a story that works as a standalone film, but also plants seeds for movies yet to come.
Han Solo's decision to join the Rebel Alliance during the film’s final battle in the trench of the Death Star makes for a compelling standalone drama but also sets many future storylines in motion. His choice makes him miss his payment to Jabba, leading Boba Fett to come after him in "Empire," and the gang freeing him from Jabba’s clutches in "Return of the Jedi.”
When making the final shot to blow up the Death Star, Luke hears Obi-Wan Kenobi's voice telling him to "use the Force '' instead of his targeting computer. The concept of the Force becomes an integral part of the expansive franchise that lies ahead.
One big way "A New Hope" left room for its sequels was by not killing Darth Vader when he is knocked off course. If he had been near the Death Star when it blew up, we never would have gotten the "No, I am your father" scene in "Empire" or his redemption arc in "Jedi."
"A New Hope" concludes with Princess Leia bestowing medals on Han and Luke, but not Chewie. Fans decried this seemingly speciesist snub for decades until Chewie finally got his own medal in "Rise of Skywalker."