When you ask industry veterans why it has been so difficult for Hollywood to turn out a new crop of megawatt male stars, the fast answer usually involves the state of movies. Stars like Matt Damon, Russell Crowe and Tom Hanks came up in medium-size dramas and comedies that let them build a fan base, the kinds of movies Hollywood has all but abandoned as it pursues bloated special-effects extravaganzas that play increasingly to an overseas audience. Actors, even good ones, get swallowed by that machinery or have trouble delivering a memorable performance because they are acting against little more than a green screen.

Then there is what Jeanine Basinger, the chairwoman of the film studies department at Wesleyan University, describes as the “pretty boy problem.” In the studio system heyday leading men were distinctive, she noted, pointing to Gable, Cary Grant, Humphrey Bogart and Jimmy Stewart. The last generation of A-listers includes quirkier types like Mr. DiCaprio, Mr. Depp and Robert Downey Jr.