Trivia: Originally Obi-Wan Kenobi survived the duel with Darth Vader and fled aboard the Millennium Falcon. But the character had very little to do with the rest of the film, and George Lucas decided that he should be killed off. Alec Guinness threatened to quit the production over the change, but Lucas convinced him that the change was better for the overall story.
Trivia: Sir Alec Guinness was apparently not a fan of the Star Wars dialogue. A letter was found in 2016 that he wrote to his friend saying "New rubbish dialogue reaches me every other day on wadges of pink paper, and none of it makes my character clear or even bearable."
Trivia: Princess Leia and Obi-Wan Kenobi never meet once in the entire film.
Trivia: When Luke is the climbing the ladder to his X-Wing fighter before the Battle of Yavin, an InCom Engineer asks him if he needs another Artoo unit. This engineer is Shane Rimmer, best known for the voice of Scott Tracy in the Gerry Anderson series "Thunderbirds".
Trivia: Scenes with the Jawa sandcrawler were shot near the border of Tunisia and Libya. Worried Libyan officials looked over the vehicle to make sure it was not part of a Tunisian military operation.
Trivia: Although Peter Cushing is listed as Grand Moff Tarkin in the end credits, he is never referred to as either Moff or Grand Moff. Throughout the film, he is simply called Governor Tarkin or Tarkin.
Trivia: Before being cast as Darth Vader, David Prowse was offered the role of Chewbacca. Prowse turned down Chewbacca, as he did not like the idea of having to wear a furry monkey costume for his part, so he chose Darth Vader, as he believed that everyone remembers the villain.
Answer: While planning Star Wars, Lucas had a vague notion of doing a long series of movies inspired by old serials, then dropped that idea in favor of just one. When Star Wars became a phenomenon and sequels became feasible, Lucas revisited the idea. He thought of three trilogies along with some stand-alone "in-between" stories for a total of 12 films. By the time of The Empire Strikes Back's release, this was pared down to the 9 mainline films, going by interviews with Lucas and the cast at the time. By Return of the Jedi, Lucas had decided to end the saga there, with the option that he could revisit the first three at some later point. It's unclear if Lucas ever had any specific story ideas for the proposed sequel trilogy, and they never had any scripts. Producer Gary Kurtz suggested in an interview they would've been about Luke's twin sister (not Leia), though many fans are skeptical about just how much he would know about them. Of course since this question was asked a sequel trilogy was written and released.
TonyPH