LOS ANGELES — Near the middle of “Oz the Great and Powerful,” James Franco, who plays the title character, surveys his bewildering surroundings and mutters “Are you kidding me?”

On Friday, when this wizard and his hot air balloon land in theaters, the Walt Disney Company hopes ticket buyers won’t think the same thing.

No movie studio would have the nerve to remake “The Wizard of Oz,” the beloved 1939 musical ranked by the Library of Congress as the most-watched film in history. But “Oz the Great and Powerful,” a Disney-produced prequel, is nearly as intrepid. The company is betting that a new twist on a story moviegoers already love will result in a hit on par with “Alice in Wonderland,” which took in more than $1 billion in 2010.

It’s a breathtaking gamble. “Oz,” at turns goofy and dark (and not a musical), cost about $325 million to make and market, according to people who worked on the movie who spoke on the condition of anonymity to avoid conflict with Disney. Mr. Franco has never anchored a mainstream movie before. Because of copyright constraints Disney was not able to reproduce certain iconic imagery from the “The Wizard of Oz,” which is owned by Warner Brothers.