Where did George Lucas get his ideas for the Jedi, The Force, the movie plots, Darth Vader? The answer is simple: Japanese movies about samurai and ninjas. See two films largely credited with inspiring the movie plots and the characters:

The 1960s were an exciting time for filmmaking in Japan. Book and films from America and Europe would inspire Japanese creators to rethink stories and characters into traditional Japanese tales. Then American and European filmmakers would be inspired by the traditional Japanese stories and rework them into Westerns and Sci-Fi. The riffing back and forth created classic, iconic films for both audiences that are still cult classics today. In addition to "Star Wars," the spaghetti Western "Fistful of Dollars" starring Clint Eastwood was inspired by the same films.

The basic idea is a hero stumbles into a situation with warring factions. He has heroic qualities, but has no side. It's not his fight. But he gets dragged into it. In "Star Wars" that's Han Solo, and to a less extant Luke, being dragged into the conflict between the Empire and the Rebellion. In "Yojimbo" the good guy is a ronin -- a samurai without a master to serve -- like Obi Wan Kenobi. He has two peasant friends who are funny (which inspired R2D2 and C3PO). He hangs back while the conflict progresses and eventually defeats the evil and saves the town at the ending. In "The Magic Serpent" an evil ninja who knows magic (Darth Vader) orphans a prince and then goes looking for him (Luke) but he keeps getting saved by magical creatures (Obi Wan) who take him to a hermit to learn magic (Yoda) and eventually he makes friends with a girl who turns out to be the daughter of the evil ninja (Vader is Luke's father, Leia is his sister). Eventually he learns enough magic to take on the evil ninja (Return of the Jedi). In another samurai film the evil general has a change of heart at the very end (Vader becoming Anakin again before dying).

George Lucas traveled to Japan in the 1960s and was greatly impressed by their art (Darth Vader's helmet is inspired by a samurai mask and all the emblems are inspired by Japanese family crests), their monsters (Godzilla became Jabba the Hut and other creatures), their religion (The Force is inspired by Taoism and Buddhism), and their stories (bounty hunters, evil magic, betrayal, etc.).

The Magic Serpent