WASHINGTON — The Supreme Court on Monday struck down on First Amendment grounds a California law that banned the sale of violent video games to children. The 7-to-2 decision was the latest in a series of rulings protecting free speech, joining ones on funeral protests, videos showing cruelty to animals and political speech by corporations.

In a second decision Monday, the last day of the term, the court also struck down an Arizona campaign finance law as a violation of the First Amendment.

Justice Antonin Scalia, writing for five justices in the majority in the video games decision, Brown v. Entertainment Merchants Association, No. 08-1448, said video games were subject to full First Amendment protection.

“Like the protected books, plays and movies that preceded them, video games communicate ideas — and even social messages — through many familiar literary devices (such as characters, dialogue, plot and music) and through features distinctive to the medium (such as the player’s interaction with the virtual world),” Justice Scalia wrote. “That suffices to confer First Amendment protection.”