Politicians and conservative groups have long condemned video games that challenge players to gun down enemies, saying that the games glorify and instigate real life violence. But scientific research on the topic has been inconclusive.
In 2011, the U.S. Supreme Court ruled that video games deserve the same First Amendment protections as books, comics, plays and other entertainment.
Most such games, called "first-person shooters," are rated M for Mature by the rating board indicating content is generally suitable for ages 17 and older. Though, of course, many younger teens play them.