The UK's Office for Fair Trading has published its final principles for how online and mobile games firms use in-app purchases and use personal data of their players.
Developers and publishers have been given two months to "get their house in order" by the OFT, as it set a deadline of 1 April for companies to make sure their games comply with existing consumer protection laws, particularly in relation to children.
The OFT originally launched an investigation into games in April 2013, after a spate of incidents involving children spending up to four-figure sums on in-app purchases in mobile games without their parents' permission.
The investigation, which included an examination of 38 web and mobile games, as well as submissions from parents and industry stakeholders, resulted in its Children's Online Games report published in September, including eight principles to help games firms abide by the law.
Among the final principles published today: games should explain any in-app purchases or advertising upfront, as well as making it clear what personal data may be shared with other companies for marketing purposes; and that in-app purchases should not be accepted without the "express, informed consent" of the payment account holder.
"The online and apps based games industry has already made significant improvements during our consultation process. But it still needs to do more to protect children and treat its customers fairly," said OFT chief executive Clive Maxwell in a statement stressing that parents have responsibilities in this area as well as games developers.
"Parents and carers have an important role to help protect their child and their bank balance. Our advice is that parents check their device settings, play their child's games themselves and read the game's description online. Parents will also be encouraged to report concerns to Citizens Advice."
British games industry body Ukie has welcomed the final principles, including the emphasis on parental responsibility as well as that of its members. "Protecting consumers is a shared responsibility across those who make and sell games, as well as parents and carers," said its chief executive, Dr Jo Twist.
"Done responsibly, micro-transaction based business models give choice and value for both players and businesses. Flexibility for companies to operate different business models is crucial, and it is good to see the OFT recognise this."
Ukie says it will run briefing sessions for games companies to help them understand how to apply the principles, including a session on 20 February in London that will be addressed by the OFT's team.
Companies who continue to indulge in shady practices will face "enforcement action" according to the OFT, which notes that from 1 April, responsibility for this enforcement will lie with the UK's new Competition and Markets Authority.
"Once the CMA acquires its powers in April 2014, we will pick up from where the OFT has left off. The CMA will continue to monitor the market to check whether the industry is complying with its legal obligations," said its chief executive Alex Chisholm.
While in-app purchases were the topical news issue when the OFT's investigation was launched in 2013, more recently the attention has shifted to the personal data being shared by games via mobile advertising networks and analytics tools.
This month, The Guardian reported that the US National Security Agency (NSA) and its UK counterpart GCHQ were targeting "leaky" apps including Angry Birds as a way to harvest more personal data from smartphone users.
• OFT report into children's games raises more questions
