Despite the title, Sam Raimi’s new Oz movie isn’t great; it isn’t even good. “Oz the Great and Powerful” is certainly splashy and colorful. But it’s also sluggish, derivative and in the end rather tedious. It resembles its titular character, who pretends to have supernatural powers but is actually just a con-man. While aiming for some of the magic that made “The Wizard of Oz” a classic, it comes off as just another crass effort to capitalize on its popularity with tricks that—given the budget—might not be cheap but are pretty lame.

The movie’s a prequel of sorts to the 1939 film. In a black-and-white, small-screen prologue, Oscar Diggs (James Franco) is a small-time magician (and full-time ladies’ man) employed in a little circus travelling around 1905 Kansas. While running away from some understandably infuriated colleagues, he takes off in a hot air balloon that gets caught up in a twister and is transported to the land of Oz, now in wide-screen and vibrant colors. There he’s immediately taken by lovely self-styled witch Theodora (Mila Kunis) to be the prophesied wizard who will become king of the Emerald City, whose benevolent ruler was recently assassinated, and save the populace from the evil powers that killed him.

Always the opportunist, Oscar embraces the role, and follows Theodora down the yellow brick road to the Emerald City, freeing winged monkey Finley (voiced by Zach Braff) along the way. (The cute little fellow, grateful for the help, volunteers to be his servant.) After meeting Theodora’s sultry sister Evanora (Rachel Weisz), Oz sets off to confront the supposedly wicked witch Glinda (Michelle Williams), along the way rescuing China Girl (voiced by Joey King), a porcelain doll that’s been badly damaged by an assault from the witch’s flying orangutans that also joins their expedition.

It turns out, of course, that Glinda’s not evil at all, and before long Oz and his companions have allied with her to save the Emerald City from the control of the two sisters, one of whom has transformed into the Wicked Witch of the West by this time. There follows a big battle in the city square in which Oz’s abilities at prestidigitation, along with his admiration for the mechanical genius of Thomas Alva Edison and his knowledge of fireworks, come in handy.

Writers Mitchell Kapner and David Lindsay-Abaire, working from the Oz books by L. Frank Baum, have tried to work as many reflections of the 1939 movie into their script as possible, and Raimi has obviously seized on them. But unfortunately they seem devoted to aping other successful big-screen models as well. The look of the picture, while certainly gorgeous (the production designer was Robert Stromberg, the supervising art directors Stefan Dechant and Todd Cherniawsky, the set decorator Nancy Haigh and the costume designers Gary Jones and Michael Kutsche, with cinematography by Peter Deming), depends entirely too heavily not only on the 1939 picture but on Tim Burton’s “Alice in Wonderland.” And when we get to the big finale, a confrontation among the witches that has an excess of knock-down fights and damsel-chained-up moments, it turns out to be way too reminiscent of the light saber stand-offs of “Star Wars” and the wizard wand battles of “Harry Potter.” And it seems to go on forever. A coda in which Oscar, newly installed as the Great Oz, hands out gifts to his pals wants to evoke the lump-in-the-throat conclusion of “The Wizard of Oz” but fails signally at it.

Maybe the picture would have come off better with a more charismatic lead, but Franco seems about as involved and energized here as he was as an Oscar host. Far from a fellow who could amaze people with his sleight of hand and seduce pretty young girls with an easy smile and easier manner, Franco seems all too lethargic and transparent. Compared to Burton’s star, he simply lacks Deppness. As to the others, Weisz has the chops to play slinky and ruthless, but Kunis proves lightweight, unable to carry off her heavy duties in the picture’s second half though she’s pretty and likable in the first; and Williams is just shy of the ethereal quality Glinda needs. And though Danny Elfman uses his customary bag of tricks in scoring the movie, they don’t create the sense of wonder he’s obviously straining to reach. The celestial chorus that appears so often is particularly irritating.

“Oz the Great and Powerful” is just the latest disappointment in the long series of Oz movies and TV shows made since Judy Garland’s. Given their overall low quality, you have to think that the defining line about them isn’t “There’s no place like home” as much as “You can’t go home again.”