As graphics get more realistic, the worry is that children won't be able to tell the difference between reality and fantasy.
And educational specialist Peter Kendall says they encourage children to solve problems using violence and hatred.
But - perhaps unsurprisingly - most gamers seem to disagree.
One gamer told the BBC: "I would not be influenced by any games to go out and do shootings and killings.
"There must be something wrong with the those people who do that, it can't be just the games."