Hilda Solis, chair of the LA County Board of Supervisors, said the lawsuit – filed by the LA County Counsel’s office – accuses Roblox of failing to moderate its platform adequately and of operating age-verification systems that are not fit for purpose.

The complaint alleges public nuisance and violations of California’s false advertising law.

Roblox, which says it has about 144 million daily active users worldwide, more than 40 percent of them under 13, has rejected the claims.

In the complaint, the county states: “Roblox portrays its platform as a safe and appropriate place for children to play.”

It continues: “In reality, and as Roblox well knows, the design of its platform makes children easy prey for pedophiles.” Announcing the legal action, Hilda said: “This lawsuit is about protecting children from online predators and inappropriate content.”

She added: “Roblox has a responsibility to keep kids safe but instead it has allowed its platform to become a place where children can be exposed to grooming and exploitation.”

The suit also quotes Dawyn R Harrison, the Los Angeles County lawyer leading the case.

Dawyn said: “This is not about a minor lapse in safety. It is about a company that gives pedophiles powerful tools to prey on innocent and unsuspecting children.

“The trauma that results is horrific, from grooming to exploitation to actual assault. This needs to stop.”

Roblox, which allows users to create, share and play games using customisable avatars and chat functions, operates a free-to-play model with optional purchases of virtual currency for upgrades.

The company has faced longstanding criticism over child safety.

A 2024 report by Hindenburg Research described the platform as an “X-rated pedophile hellscape” that exposed children to grooming and pornography.

In a statement to AFP, Roblox said it contests the allegations and that the platform was built “with safety at its core.”

A spokesperson said: “We have advanced safeguards that monitor our platform for harmful content and communications, and users cannot send or receive images via chat, avoiding one of the most prevalent opportunities for misuse seen elsewhere online.”

The spokesperson added: “There is no finish line when it comes to protecting kids and, while no system can be perfect, our commitment to safety never ends.”

The lawsuit comes as a separate trial unfolds in Los Angeles in which social media companies, including Facebook, are being sued over claims their algorithms target young teenagers with addictive content.