Washington (CNN) -- The Supreme Court has struck down a California law that would have banned selling "violent" video games to children, a case balancing free speech rights with consumer protection.

The 7-2 ruling Monday is a victory for video game makers and sellers, who said the ban -- which had yet to go into effect -- would extend too far. They say the existing nationwide, industry-imposed, voluntary rating system is an adequate screen for parents to judge the appropriateness of computer game content.

The state says it has a legal obligation to protect children from graphic interactive images when the industry has failed to do so.

"As a means of assisting concerned parents it (the law) is seriously overinclusive because it abridges the First Amendment rights of young people whose parents (and aunts and uncles) think violent video games are a harmless pastime," wrote Justice Antonin Scalia for the majority.

Supreme Court sees video games as art

In dissent, Justice Stephen Breyer framed the law's intent differently.

"The First Amendment does not disable government from helping parents make such a choice here -- a choice not to have their children buy extremely violent, interactive games," he wrote.

At issue is how far constitutional protections of free speech and expression, as well as due process, can be applied to youngsters. Critics of the content-based restrictions say the government would in effect be engaged in the censorship business, using "community standards" to evaluate artistic and commercial content.

A federal appeals court in San Francisco last year tossed out the law before it took effect, after then-Gov. Arnold Schwarzenegger signed it in 2005. He had applauded the high court's decision to intervene. "We have a responsibility to our kids and our communities to protect against the effects of games that depict ultraviolent actions, just as we already do with movies," the governor said. The onetime actor made his name playing characters engaged in similarly violent acts in such movies as "Terminator."

The legislation was designed to strengthen the current industry-controlled rating system, and would have placed an outright ban on the sale or rental to those under 18 of games deemed excessively "violent." As defined by California, such interactive games are those in which the player is given the choice of "killing, maiming, dismembering or sexually assaulting an image of a human being" in offensive ways. It also defined such games as those that would "appeal to a deviant or morbid interest of children and are patently offensive to prevailing community standards."

Retailers would have faced up to $1,000 fine for violations. The law would also have required game makers and retailers to place an "18" label prominently on excessively violent games.

In an unusual coalition, Scalia's majority opinion had the support of Justices Anthony Kennedy, Ruth Bader Ginsburg, and Sonia Sotomayor.

Scalia noted the court had never permitted government regulation of minors' "access to any forms of entertainment except on obscenity grounds."

He said the California law was one of many similar ones over the years, which he called "failed attempts." He cited movies, comic books, television, music lyrics, even Grimm's fairy tales and "Snow White," for their violent content.

But Justices Samuel Alito and Chief Justice John Roberts, while agreeing California went too far, nevertheless suggested a more narrowly tailored law might meet free-speech scrutiny.

"We should make every effort to understand the new technology" presented in these sophisticated video games, said Alito.

Along with Breyer, Justice Clarence Thomas also dissented, saying the law's requirement of having parents purchase the games for their underage children was reasonable. "The freedom of speech as originally understood, does not include a right to speak to minors, without going through the minors' parents or guardians," he said.

The gaming industry sued in federal court and won an injunction halting enforcement of the law until the courts sorted out the constitutional questions. The game "Postal 2" was specifically cited by the state as potentially subject to the proposed statutory ban. The manufacturer, Running With Scissors, Inc., based in Tucson, Arizona, rates it as "M" for a mature audience only, with "blood and gore," "intense violence" and "sexual themes" as part of its content.

Other games listed by parent groups as being of concern are "Full Spectrum Warrior" and "Call of Duty: Modern Warfare 2," where players at one level can view terrorists slaughtering civilians at an airport.

The video game industry, as part of its appeal, sent several PlayStation video games to the justices to view, including "Medal of Honor" and "Resident Evil 4."

The game industry racks up $10.5 billion in yearly sales. The industry claims more than two-thirds of households have at least one member who plays video games.

The motion picture industry has its own self-monitoring ratings system, imposed decades ago after complaints that some films were too explicit for the general audience in what was seen and heard. The gaming industry says its ratings system roughly follows the same self-imposed guidelines, and ratings are clearly labeled on the packaging.

Similar complaints have been raised over the decades over children's exposure to pulp novels and comic books, in addition to pornography.

Efforts in at least eight other states to restrict gaming content have been rejected by various courts. Video game makers have the support of various free-speech, entertainment, and media organizations. Nine states also agree, noting California's law has good intentions but would compel law enforcement to become "culture critics" and "distract from the task of policing actual violence."

But 11 other states back California, saying they have enjoyed a traditional regulatory power over commerce aimed at protecting children, including such goods as alcohol and cigarettes.

The Supreme Court in recent years has thwarted repeated congressional attempts to protect children from internet pornography, saying legislation went too far in limiting adult access to lawful, but explicit, sexual content on the Web.

And the justices this spring threw out a federal law limiting the sale of graphic videos of animal cruelty.

The case is Brown v. Entertainment Merchants Assn. (08-1448).