In-game purchasing systems, such as 'loot boxes', in popular online games resemble gambling and may pose financial risks for vulnerable players, according to gambling psychology researchers at the University of Adelaide.

The researchers have examined a range of popular online games that include the option of paying small fees ('microtransactions') to access additional features or content that enhance the player's experience.

In an editorial published today in the journal Addiction, the researchers say some online games enable endless spending behaviours and employ systems that disguise or withhold the long-term cost of these microtransactions.

The true financial cost of such games may not be obvious until the player is financially or psychologically committed and then finds it more difficult to stop.

"These schemes may entice some players to spend more money than they may have intended or can afford, especially when using credit cards or virtual currency that makes it hard to keep track of spending," says Dr Daniel King, Senior Research Associate in the University of Adelaide's School of Psychology.

He and fellow author Professor Paul Delfabbro, also from the School of Psychology, focus on a purchasing scheme called the 'loot box', an in-game reward system in which players can repeatedly buy a random selection of virtual items.

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