The Culture, Media and Sport committee demanded an end to the sale of “loot boxes” – items which change a character or its abilities and which can be bought with real money – to those underage, as it amounted to “gambling”.
They said since the features do not always reveal their contents in advance, they “contain the element of chance” and therefore should only be paid for through in-game credits.
The committee said evidence showed while the features are “integral” to games firms’ profits, they affected problem gamblers.
In a blast at the industry, it said gaming companies were “several years behind gambling in relation to protecting the vulnerable” and said some representatives had been “wilfully obtuse”.
Their report cited a case of a man who built up debts of more than £50,000 through spending on microtransactions in online game, RuneScape.
MPs added that while there was an “absence of research” on potential harms caused by exposing children to gambling, ministers should take a precautionary approach.
They also called for firms to pay towards research into long-term effects of gaming and specifically “gaming disorder”, since it had “not sufficiently accepted responsibility” for either understanding or preventing this harm.
Elsewhere they added that fresh legislation could be needed to ensure age-ratings are enforced since online games “are not subject to a legally enforceable system”, with voluntary ratings used instead.
DCMS Committee chair Damian Collins said: “Loot boxes are particularly lucrative for games companies but come at a high cost, particularly for problem gamblers, while exposing children to potential harm.
“Buying a loot box is playing a game of chance and it is high time the gambling laws caught up. We challenge the Government to explain why loot boxes should be exempt from the Gambling Act.”
The MP said it was “unacceptable” that companies with millions of users were “ill-equipped” to recognise the effects of their products.
“Gaming disorder based on excessive and addictive game play has been recognised by the World Health Organisation,” Mr Collins added.
“It’s time for games companies to use the huge quantities of data they gather about their players, to do more to proactively identify vulnerable gamers.
He continued: “Both games companies and the social media platforms need to establish effective age verification tools. They currently do not exist on any of the major platforms which rely on self-certification from children and adults.”
The Department for Culture, Media and Sport has been approached for comment.