The result is that the best games tend to be addictive, as playersare so strongly motivated to continue the play that they find it difficult to get back to their normalactivities (Grüsser, Thalemann, & Griffiths, 2006; Kim, Namkoong, Ku, & Kim, 2008).

In some cases, though, great amounts of time playing video games (or doing any other single thing) can be evidence of something missing in a person's life. In some cases people engage in an activity not just because of their enjoyment of it, but also because it is an escape from something painful in their lives or is the only route available to them to satisfy basic psychological needs. This can occur for adults as well as children. The activity that seems to become obsessive might be video gaming, or it might be something else. For instance, some adults devote far more time to their careers than they otherwise might, because that allows them to avoid an unpleasant family environment. Some kids say they play video games at least partly as a means of escape, and some say they do so because it is the only realm of activity in which they feel free.[5] In an age in which children are often not allowed to play freely outdoors, and in which they are more or less constantly directed by adults, the virtual world of video games is for some the only realm where they are allowed to roam free and explore. If they were allowed more autonomy in the real world, many of them would spend less time at video games. As illustration of this idea, British gaming researcher Richard Wood gives some case examples.[6] One case is that of Martin, an 11-year-old boy whose mother became concerned about the huge amounts of time he was devoting to World of Warcraft and therefore forbade him from playing it or other video games, which made things only worse for Martin. It turned out, according to Wood, that Martin was an only child who was being bullied at school and hated going there, and who was afraid of going outside at home because of repeated bullying. The online video game was his only source of free expression and his only satisfying contact with other people. When this was taken away from him, he was understandably distraught. Another example is that of Helen, a 32-year-old MD who worked in a temporary research position and spent most of her spare time playing the MMORPG Final Fantasy alone in her apartment. It turned out that Helen had recently experienced a bad breakup with a long-term partner, was unhappy with her job, and was severely depressed. Playing Final Fantasy was not cause of her depression, but was her way of coping with it during this difficult time in her life. The online game provided social connections and pleasure at a time when nothing else did. In a study of more than 1300 adult video gamers (age 18 to 43), Andrew Przybylski and his colleagues at the University of Rochester found that a small percentage of them, who played many hours per day, described themselves as obsessively engaged--they felt that they didn't just "want" to play, but "needed" to play.[7] These players, when they stopped a session of playing, did not feel refreshed and energized as other players did, but felt tense and unhappy. The extensive questionnaires used in this study also revealed that these "obsessed" player were, in general, those whose basic psychological needs--their needs for freedom, competence, and social relationships--were not being met in real life. So, if your child or another loved one seems obsessed about video games and unhappy outside of the games, don't jump to the conclusion that the games are cause of the unhappiness. Instead, talk with your loved one and try to find out what might be missing or wrong in other aspects of his or her life and whether or not you can help to solve that problem.

To counteract the stereotype, Langlois points out that video gaming is hard fun, not easy fun. In his words: "This hard fun would not be possible if gamers were truly lazy or apathetic. And the level of detail that many gamers pay attention to is staggering, whether it be leveling a profession to 525 in WoW, unlocking every achievement in Halo 3, or mapping out every detail in the EVE universe. This is not apathy, this is meticulousness." So, Langlois helps gamers by helping them feel good about their gaming rather than bad about it. There is no reason why a dedicated video gamer should feel any worse about his or her hobby than a dedicated chess player or skier. Still, of course, some people let their dedication to video gaming--or to chess, or to skiing, or to anything else--interfere with other aspects of their life, and that can be a problem. Lots of us need to learn time management, especially as we reach adulthood, in order to do what we want to do and still fulfill our obligations to others. My loved ones sometimes remind me that it's not fair for me to spend all of my time reading and writing or going off alone bicycling or skiing. But, let's not stigmatize any of this by calling it an addiction. Let's just call it a time management problem and figure out constructive ways to deal with it.

Video-game designers have also mastered another trick to encourage more play: requiring an unpredictable number of actions in order to earn a reward. Giving one at regular intervals means that a player, having received a reward, will be less motivated to play on knowing that another is a long time coming. In Diablo, Dr Hilgard explains, a player may find a powerful weapon either after the very next monster that is slain, or not until a thousand monsters later. This schedule fosters more frequent engagement. Therefore the structure of reward patterns in different games may cause certain ones to be more addictive (particularly to gamers who are motivated by the prospect of completing goals and accumulating rare items).

Another risk factor is found in players with strong social motivation. Some games involve social obligations, where players have to work together. This can mean a player feels obliged to play along as the rest of the group wants to play. Farmville strives to ensure participation at regular intervals by making gamers dependent on each other for daily allotments of fantasy resources, says Joseph Hilgard, at the University of Missouri-Columbia, and colleagues in a recent paper in Frontiers in Psychology. Putting together role play and social use in one game should yield a highly compelling game. World of Warcraft, a massive multiplayer online role-playing game, fits this description and is, anecdotally, pretty addictive. 

Players are motivated by the extent to which different games fulfill their basic psychological needs; but some factors, more than others, are found in addiction. One risk factor is found in players who are trying to "escape" through fantasy immersion or role play. Indeed, their game use may be a symptom of some other underlying problem, say social phobia or depression. Playing can then generate a vicious cycle that is hard to treat if the game is a way of self-medicating. For example, a child who is unpopular in school, or being bullied, may be important and powerful in a video game. Real life may struggle to compete. 

Human psychology tells us that players should enjoy a game that satisfies the need for control, bestows a sense of one's progress, and fosters relationships with friends and others encountered. Yet gamers differ in their individual needs. Each person has their own "player personality" and this variation has spawned a vast industry designed to meet different motivations. Some may want to release aggression (Call of Duty), escape reality (World of Warcraft) or oversee building projects (Minecraft). Others are more motivated by in-game rewards, or have a high "loss aversion" and so find a challenging game unfair or frustrating (while others find it thrilling). A game like Flappy Birds, will most appeal to those who are attracted by repetitive actions, difficulty and have a low loss aversion. Those who have a high loss aversion, however, will find it infuriating.