Not long ago, it was inconceivable that video games would be anything more than a niche pastime, let alone a path to a lucrative career. Yet e-sports now attract millions of fans and major brand sponsorships. How did they come to rival to traditional sports? And can they achieve mainstream success?

Strategy-based video game Civilization V is set to be introduced to US schools in 2017. The game sees players take control of a nation and lead it to supremacy via diplomacy, trade, war or the pursuit of knowledge. And educators believe it could be used as a conduit for learning about history.

The word 'gamer' might make you think of teens in darkened bedrooms. In reality, over 60% of all American gamers are adults, and the average gamer is a 30-year-old with a job and family. But why do we play games beyond childhood? And is the way we play as adults any different?

Parents have long been reluctant to let their kids play violent games for fear of them having a negative effect on their behaviour. But recent research suggests that the link between anti-social behaviour and violent video games is a lot weaker than people thought – if it exists at all.