Young X-Men don't have the same box-office superpowers as their older selves.
"X-Men: First Class" had a solid No. 1 opening with a $56 million weekend, according to studio estimates Sunday.
But the 20th Century Fox prequel chronicling the formative years of the comic-book mutants found smaller audiences than the franchise's first four big-screen adventures, which featured older versions of the X-Men.
Debut weekends for the last three "X-Men" flicks ranged from $85.1 million to $102.8 million. The original "X-Men" opened 11 years ago with $54.5 million, but that would amount to about $80 million today adjusting for ticket-price inflation.
Fox distribution executive Chris Aronson said the studio achieved its goal of opening the prequel at about the same revenue numbers as the original "X-Men."
"This is just an excellent start in launching a brand new chapter of the 'X-Men' franchise," said Aronson, dismissing comparisons to the $85.1 million debut of Hugh Jackman's "X-Men Origins: Wolverine" in 2009.
"You can't compare this one to any of the other 'X-Men' movies, except maybe" the first one, Aronson said. "Something like 'Wolverine' is a totally unfair comparison because that had a bonafide worldwide star in Hugh Jackman and arguably the most popular character in the 'X-Men' stable."
The prequel presents a rising cast of new talent rather than the established stars of the franchise's previous chapters.
"X-Men: First Class" features James McAvoy and Michael Fassbender as Marvel Comics mutants Professor X and Magneto, roles originated by Patrick Stewart and Ian McKellen in the characters' older years.
The prequel follows their first meeting, early alliance and eventual falling out as they take opposite approaches in their dealings with ordinary humans fearful of the superpowered mutants.
The movie added $64 million from 74 overseas markets for a worldwide total of $120 million.
The previous weekend's top movie, the Warner Bros. sequel "The Hangover Part II," fell to second-place with $32.4 million. That raised its domestic total to $186.9 million but represented a steep 62 percent drop from its huge opening weekend.
Still, with overall receipts rising for the fourth-straight weekend, Hollywood continued on a summer box-office tear that has helped studios recover from a dismal first quarter.
Domestic revenues totaled $164 million, up 27 percent from the same weekend a year ago, when "Shrek Forever After" was No. 1 with $25.5 million, according to box-office tracker Hollywood.com.
"We're definitely on a roll compared to the first quarter, when we were so used to having one down weekend after another," said Hollywood.com analyst Paul Dergarabedian.
Hollywood continued to close the gap between revenues this year and last year. Receipts through Sunday totaled $4.2 billion, off 7 percent compared to 2010's.
Earlier this year, revenues had been down by more than 20 percent as a weak lineup failed to live up to 2010's big winter releases.
DreamWorks Animation and Paramount's sequel "Kung Fu Panda 2" slipped from second- to third-place in its second weekend with $24.3 million. The animated adventure raised its domestic total to $100.4 million.
Also crossing the $100 million mark was Universal's comedy "Bridesmaids," which held up well in its fourth weekend with $12.1 million. That lifted its domestic haul to $107.3 million.
The year's top-grossing film domestically, Universal's action sequel "Fast Five," pulled in $3.2 million and crept past the $200 million mark.
But Disney's sequel "Pirates of the Caribbean: On Stranger Tides" is closing in, grossing $18 million to raise its domestic take to $190.3 million.
Both movies have done far more business overseas, with the latest "Pirates" installment now at a worldwide total of $790.7 million and "Fast Five" climbing to $568.6 million globally.