Children discover the world and develop their sense of self through play and therefore, online games/video games can play a significant role in their development. However, there has been continuing debate and much concern about the world of online games and children's exposure to screen media (screen time), especially regarding video games with violent content and their effect on children and young people. While there has been extensive research in this area, some of the current arguments resemble moral panic. Indeed, concern for children's exposure to media with violent content is not a new phenomenon – for example, Bugs Bunny cartoons were contested as containing too much violence, and comic books labelled as corrupting young people and causing crime. Although Looney Tunes cartoons may have been ‘more brutal than you remember’ (Slate, 2014), and notwithstanding some level of moral panic, parents and professionals face the challenging task of safeguarding and supporting children in this dynamic and evolving landscape to ensure their healthy development.

The use of video games has consistently and significantly increased over time, and today they are a pervasive form of entertainment used by most children and young people (Pew Research Center, 2015), with continued debate about the negative effect of the games children play. A recent study found that four in ten adults believe that violence in video games leads to violent behaviour – 32 per cent play video games themselves, and 26 per cent self-identified as gamers (Pew Research Center, 2015). While a large body of research has found significant short- and long-term effects associated with video games, including a relationship between violent video games and post-game violence (Anderson et al, 2012), there are other studies that challenge these findings.

Given the large number of children and young people who play video games and the amount of time they spend playing them (Pew Research Center, 2015), it is important that practitioners have a critical and constructive approach and evidence-based understanding of the effects of online/video games and their associated risks and significance for children and their development. Therefore, in this chapter we offer an evidence-informed and systematic approach to examining the effects of online/video games. We begin with a brief description of gamification followed by a brief review of some theoretical explanations for the effects of online/video games.