“What are you going to spend it on?” I asked my 15-year-old cousin, who had just received a ￡50 Xbox gift card. He already had it all planned out — he’d convert the money into Apex Coins, the in-game currency of online shooter Apex Legends. This game is free to play but offers all manner of opportunities for players to fritter away cash, including buying “Apex Packs”, which contain three random items. You don’t know what you’ve paid for until you open the loot box.

I watched as he opened 100 boxes, each accompanied by audiovisual pyrotechnics reminiscent of slot machines. After investing ￡50, he only received a single rare item, and even that was a repeat of something he had already. I couldn’t help feeling this was money down the drain. At his age I might have used that money to buy a new game which would provide hours of fun — though I did also buy Pokémon cards, the loot boxes of my era, which often contained little of value.

Loot boxes such as those in Apex Legends are at the centre of a heated debate that has prompted legislative action in Europe and Asia. Critics say they are unethical and exploitative, little more than gambling for children. Yet the underlying mechanisms that make loot boxes so alluring can be found in many games, employed as tools to keep players engaged. In this form they are mostly benign. How do game developers draw on behavioural psychology to get players hooked? And at what point do these techniques cross the line into exploitation?