What wouldn't you do for your kid? You hold his hand crossing the street, keep him from sticking his finger in light sockets and try to get him to eat a vegetable or two. But do you know how to police his video game choices? Do you know what's out there? What are the worst video games to buy for children?

There is some controversy over whether video games cause negative or violent behavior. A 2010 study in the medical journal Pediatrics shows a pinch of both good and bad effects among adolescent gamers. On the bright side, gamer boys (76 percent of the study population) showed no negative behaviors and less inclination to start smoking. Girls didn't fare as well; though less likely to report depression, gamer girls were more prone to fighting or carrying a weapon to school.

Fortunately, games are subjected to a rating scale to give you an idea of what's appropriate for your kid and what's not. The Entertainment Software Rating Board, ESRB, seeks to give consumers impartial information about video games and mobile apps. Here's the rundown:

  • EC or Early Childhood. These games were made for kids in preschool, with no content that parents would find inappropriate.
  • E or Everyone. With very minimal use of cartoon or fantasy violence, these games are deemed appropriate for everyone over age 6.
  • E10+ or Everyone 10+. Games tagged E10+ may contain cartoon or fantasy violence, mild language and/or minimal suggestive themes.
  • T or Teen. For the 13+ age group, you might find mild violence, language and suggestive themes as well as some crude humor and a little bit of blood and gore.
  • M or Mature. In this category, content may be suitable for those 17 and older. These games can have violence, adult/crude language, sexually explicit content and intense violence, blood or gore.
  • AO or Adult Only. You must be 18 or older to buy these video games, as they are likely to contain intense violence, graphic sexual content or nudity.

Essentially, kids shouldn't be playing video games intended for older audiences. But how do you know what games are the worst to buy? If you aren't video game-savvy and think the Halo game series is about angels, it's a good idea to brush up on some of the latest games available. Obviously, you should avoid M and AO games. In addition, many game names are dead giveaways, like Assassin's Creed and Mortal Kombat. To help, here is a list of some of the worst video games rated Teen that you should NOT buy for your young gamer:

  • Aliens vs. Predator. If killing aliens on other worlds is your thing, then Aliens vs. Predator is for you. Buying it for your young kid? Not so much. It's a first-person shooter game with the goal of (you guessed it!) shooting as many aliens as possible. Available for PCs as well as the handheld PSP.
  • Battlefield 2142. A Windows game set 135 years in the future, shooters battle the computer and each other, unlocking better equipment with each kill. Rewards for killing? NOT something you want to teach your kid.
  • Call of Duty 3. This game, available for Wii, Xbox360 and Playstation 3, is yet another "shoot 'em up" game set in lifelike warzones with stunningly realistic sounds. Intense combat sequences and addictive online play make this a dangerous choice.
  • Need for Speed: Most Wanted. Most Need for Speed games have you racing against fellow street racers, but in Most Wanted, the idea is to get away from the cops. For many parents, this is a judgment call. There isn't a lot of violence, but the game centers around illegal activity. You decide.
  • Combat Missions: Shock Force. This is one complicated game that might be way over your kid's head anyway, but it's worth knowing about. Available for Windows, it's a military simulation game: you're responsible for commanding troops, calling in reinforcements, setting strategies and winning wars. It's a war game, plain and simple, and not one you'd want your kids playing.
  • Tom Clancy's Ghost Recon Advanced Warfighter. Just like the name suggests, this is a war game in all its glory. Though rated Teen, this Xbox 360 game has players completing search-and-destroy missions, sniping and leading team members into combat.
  • Daemonica. Sure to give any kid nightmares for days, Daemonica is an action-adventure game for your PC that involves talking to the dead. You play a medieval sleuth who solves crimes by talking to the corpses and drinking deadly potions. It's not gory, and since characters are already dead you aren't killing them, but it's a too full of nightmarish creatures to be suitable for children.

These games are just a sampling of what's out there, and you should use your best judgment. And even if your child is exposed to the "worst" game, it's not the end of the world. According to Brandon Yorty, M.S., a board certified behavior analyst, behavior must be reinforced for it to become a habit. For instance, if your daughter watches a video game and then acts out a scene from it to her friends, their response is more likely to shape her future behavior choices than the video game itself. If the friends clap or positively respond, she may be inclined to repeat it, and with more gusto.

So, why not start your own positive reinforcement of game behavior that you approve? Though you can't be with him all the time, you can make sure your child plays only appropriate games at home. You are his best role model, so you show him what's right.