An advertisement for the "Grand Theft Auto 4" video game sits on display at a store in New York April 28, 2008. REUTERS/Shannon Stapleton

LOS ANGELES (Reuters Life!) - A U.S. appeals court ruled a California law restricting the sales and rental of violent video games to minors and imposing labeling requirements is too restrictive and violates free speech guarantees.

The Ninth U.S. Circuit Court of Appeals found Friday that the labeling requirement unfairly forces video games to carry “the state’s controversial opinion” about which games are violent.

The unanimous opinion by a three-judge panel could have a far-reaching impact on efforts by other states to establish mandatory video game labeling requirements.

The court upheld a lower court finding that California lawmakers failed to produce evidence that violent video games cause psychological or neurological harm to children.

“Even if it did, the Act is not narrowly tailored to prevent that harm and there remain less restrictive means of forwarding the state’s purported interests,” the court wrote.

Those alternative measures include the voluntary ratings system established by the Entertainment Software Rating Board, educational campaigns and parental controls, the court said.

The 2005 law, which requires games described as violent to carry an “18” label, has been contested by video game publishers, distributors and sellers.