The U.S. Supreme Court is about to jump into the controversial world of kids, joysticks and violent video games such as "Grand Theft Auto" and "Call of Duty: Modern Warfare."

In a case that pits the right to limit children's exposure to video-game mayhem against traditional free speech protections, the Supreme Court on Monday agreed to consider the constitutionality of a 2005 California law barring the sale or rental of violent video games to minors.

"Quite a few states feel this needs to be regulated, and I think (the justices) might be saying this is an issue of national importance," said Eugene Volokh, a UCLA law professor who has followed the case closely. "That this is the sort of thing that ought to be decided by the Supreme Court."

The justices will review a decision last year by the 9th U.S. Circuit Court of Appeals, which struck down the law, concluding it trampled on free speech rights and that California had not proven enough connection between violent video games and youth troubles to show the state had a "compelling interest" in such strict regulation. A San Jose federal judge previously put the law on hold shortly after it went into effect.

Despite the fact lower courts around the country have consistently invalidated similar laws, the Supreme Court decided to hear the Schwarzenegger administration's appeal, which argued California has the right to limit "ultraviolent" material sold to minors. State Sen. Leland Yee, D-San Francisco and author of the law, also had urged the justices to take the case.

Yee said Monday that California's law, because it only restricts sales to minors, should be narrow enough to hold up in the Supreme Court. At least six other states have enacted similar laws, which target games replete with images of bloody, graphic violence that includes killing and maiming characters.

"These games are hurtful for kids," he said.

Game violence has been getting increasingly graphic in recent years, as video games have become more realistic and as the industry has shown fewer inhibitions about depicting bloodshed. "Call of Duty: Modern Warfare 2" includes an optional level where players watch as terrorists massacre civilians at an airport, shooting some in the back of the head. Another recent game, "Dante's Inferno" includes a level where players slash and stab demonized babies. And in "Gears of War," players can use a chain saw bayonet to slash enemies and slice them in half.

The video game industry, which has fought to overturn the law, criticized the state's appeal as a move to threaten free speech protections, not only for video games but also for movies, books, music and other artistic material. Critics of the law also say it's an attempt to supplant the role of parents in deciding what video games their children can play.

"We have the opportunity to make our case again and hopefully put this issue to rest," said Mike Gallagher, CEO for the Entertainment Software Association, the video game industry's trade group.

Some parents say they support the law because the industry's own labeling system for video games may not be enough, while others say parents — not the state — should handle the controls.

"There's no way to block what (kids) are getting," said Lisa Pelgrim, a San Jose mother of three children who played games on their Nintendo Wii until it broke. "I don't let my kids watch violent TV, and games are even more interactive and real than the TV."

Robin Wolaner, who founded Parenting magazine and has a 16-year-old son and 11-year-old daughter, is concerned about violent games, but doesn't think laws such as California's can replace parental responsibility.

"They trample on the constitution or they trample on common sense," said the 55-year-old San Francisco woman.

The law would prevent those younger than 18 from buying or renting video games that "appeal to a deviant or morbid interest of children and are patently offensive to prevailing community standards." Retailers would face a $1,000 fine for violations. In addition, the law would require video game publishers to put an "18" label prominently on excessively violent video games.

Legal experts say the outcome in the Supreme Court is uncertain. The justices often are reluctant to curtail First Amendment rights, as they showed last week in a decision striking down a federal ban on video depictions of animal cruelty. At the same time, legal experts say they may find a state's argument for limiting the sale of violent material to minors appealing, as long as it doesn't go too far.

Brad Joondeph, a Santa Clara University law professor, said the case will not necessarily fall into the usual liberal vs. conservative divide inside the court.

"This is different," he said. "This is one of those cases that's a hot-button issue that is not predictable."

The Supreme Court will be in largely uncharted territory, having considered restrictions on sexually explicit material through the years but not violent images common in a host of new video games. Attorney General Jerry Brown has argued that regulating violent video games should be "subject to the same flexible legal standard" applied to sexually explicit material sold to children.

The 9th Circuit, in the decision written by Judge Consuelo Callahan, an appointee of former President George W. Bush, found that California officials did not establish a scientific connection between violent video games and physical and psychological harm to minors. And the court found the law's definition too vague.

Volokh said the 9th Circuit may have been correct in finding that the California law is simply too broad in its reach. Referring to the ban on sales of video games that "appeal to a deviant or morbid interest of children," he said: "It's extremely hard to tell what that would mean."

Mercury News Staff Writer Chris Strach contributed to this report. Contact Howard Mintz at 408-286-0236.