Reality is Broken explains the science behind why games are good for us--why they make us happier, more creative, more resilient, and better able to lead others in world-changing efforts.

But some games are better for us than others, and there is too much of a good thing.

Here are a few secrets that aren’t in the book to help you (or the gamer in your life) get the most positive impact from playing games.

This practical advice--5 key quidelines, plus 2 quick rules--is scientifically backed, and it can be summed up in a single sentence:

Play games you enjoy no more than 21 hours a week; face-to-face with friends and family as often as you can; and in co-operative or creator modes whenever possible.

1. Don’t play more than 21 hours a week.

Studies show that games benefit us mentally and emotionally when we play up to 3 hours a day, or 21 hours a week. (In extremely stressful circumstances--such as serving in the military during war-time--research shows that gamers can benefit from as many as 28 hours a week.) But for virtually everyone else, whenever you play more than 21 hours a week, the benefits of gaming start to decline sharply. By the time you’re spending 40 hours or more a week playing games, the psychological benefits of playing games have disappeared entirely--and are replaced with negative impacts on your physical health, relationships, and real-life goals. So always strive to keep your gaming in the sweet spot: 7–21 hours a week.

2. Playing with real-life friends and family is better than playing alone all the time, or with strangers.

Gaming strengthens your social bonds and builds trust, two key factors in any positive relationship. And the more positive relationships you have in real life, the happier, healthier and more successful you are.

You can get mental and emotional benefits from single-player games, or by playing with strangers online--but to really unlock the power of games, it’s important to play them with people you really know and like as often as possible.

A handy rule-of-thumb: try to make half of your gaming social. If you play 10 hours a week, try to play face-to-face with real-life friends or family for at least 5 of those hours.

(And if you’re not a gamer yourself--but you have a family member who plays games all the time, it would do you both good to play together--even if you think you don’t like games!)

3. Playing face-to-face with friends and family beats playing with them online.

If you’re in the same physical space, you’ll supercharge both the positive emotional impacts and the social bonding.

Many of the benefits of games are derived from the way they make us feel--and all positive emotions are heightened by face-to-face interaction.

Plus, research shows that social ties are strengthened much more when we play games in the same room than when we play games together online.

Multi-player games are great for this. But single-player works too! You can get all the same benefits by taking turns at a single-player game, helping and cheering each other on.

4. Cooperative gameplay, overall, has more benefits than competitive gameplay.

Studies show that cooperative gameplay lifts our mood longer, and strengthens our friendships more, than competing against each other.

Cooperative gameplay also makes us more likely to help someone in real life, and better collaborators at work--boosting our real-world likeability and chances for success.

Competition has its place, too, of course--we learn to trust others more when we compete against them. But if we spend all our time competing with others, we miss out on the special benefits of co-op play. So when you’re gaming with others, be sure to check to see if there are co-op missions or a co-op mode available. An hour of co-op a week goes a long way. (Find great co-op games for every platform, and a family-friendly list too, at Co-Optimus, the best online resource for co-op gaming.)

5. Creative games have special positive impacts.

Many games encourage or even require players to design and create as part of the gameplay process--for example: Spore, Little Big Planet, and Minecraft; the Halo level designer and the Guitar Hero song creator. These games have been shown to build up players’ sense of creative agency--and they make us more likely to create something outside of the game. If you want to really build up your own creative powers, creative games are a great place to start.

Of course, you can always take the next creative step--and start making your own games. If you’ve never made a game, it’s easier than you think--and there are some great books to help you get started.

2 Other Important Rules:

* You can get all of the benefits of a good game without realistic violence--you (or your kids) don’t have to play games with guns or gore.

If you feel strongly about violence, look to games in other genres--there’s no shortage of amazing sports, music, racing, puzzle, role-playing, casual, strategy and adventure games.

*Any game that makes you feel bad is no longer a good game for you to play.

This should be obvious, but sometimes we get so caught up in our games that we forget they’re supposed to be fun.

If you find yourself feeling really upset when you lose a game, or if you’re fighting with friends or strangers when you play--you’re too invested. Switch to a different game for a while, a game that has “lower stakes” for you personally.

Or, especially if you play with strangers online, you might find yourself surrounded by other players who say things that make you uncomfortable--or who just generally act like jerks. Their behavior will actually make it harder for you to get the positive benefits of games--so don’t waste your time playing with a community that gets you down.

Meanwhile, if you start to wonder if you’re spending too much time on a particular game – maybe you’re starting to feel just a tiny bit addicted--keep track of your gaming hours for one week. Make sure they add up to less than 21 hours! And you may want to limit yourself to even fewer for a little while if you’re feeling too much “gamer regret.”