Video gaming giants have been the subject of a consumer group’s complaint for their “sneaky tactics” that encourage users to spend more money on games.

The complaint filed by the European Consumer Organisation (BEUC) and 22 of its members across the region has raised concerns against the likes of Supercell, Ubisoft, Electronic Arts, and Epic Games, which develop some of the most popular games: Minecraft, Fortnite, and Assassin’s Creed.

The complaint to European Union authorities accuses them of breaching laws by misleading users into spending money. BEUC claims that microtransactions, in which consumers are nudged into buying in-game currencies with real money, result in overspending.

The world of video games “shouldn’t be a place where companies bend the rules to increase profits,” said Agustín Reyna, the director of BEUC, suggesting that companies should display the amounts in real currency terms so gamers aren’t left confused.

Reyna said the main concern with how video games currently operate their in-game currencies is that children get caught in them.

“Companies are well aware of children’s vulnerability and use tricks to lure younger consumers into spending more,” he said.

In-game purchases rake in $50 billion globally—that’s nearly a quarter of the entire video gaming market’s revenue, BEUC said. About 84% of those aged 11 to 14 years are into video games, making them a large chunk of the audience.

In Europe, children spend roughly €39 a month on in-game purchases because of video gaming companies’ “manipulative” ways.

Children are, therefore, directly impacted by the convoluted system of in-game currencies as they simultaneously lack the financial literacy to make informed purchasing choices, the consumer group highlighted.

When video gaming became popular decades ago, it often involved one-off purchases from a store after which gamers used their consoles to enjoy the game without recurring expenses. But in recent times, as video gaming has shifted to a digital model, purchases have been somewhat baked into the gaming experience—especially among freely downloadable games. Consumers have pushed back against the practice that has now become commonplace across the most popular games.