Loot boxes are purchased in video games to obtain randomised rewards of varying value and are thus psychologically akin to gambling. Disclosing the probabilities of obtaining loot box rewards may reduce overspending, in a similar vein to related disclosure approaches in gambling. Presently, this consumer protection measure has been adopted as law only in the People's Republic of China (PRC). In other countries, the videogaming industry has generally adopted this measure as self-regulation. However, self-regulation conflicts with commercial interests and might not maximally promote public welfare. The loot box prevalence rate amongst the 100 highest-grossing UK iPhone games was 77% in mid-2021. The compliance rate with probability disclosure industry self-regulation was only 64.0%, significantly lower than that of PRC legal regulation (95.6%). In addition, UK games generally made insufficiently prominent and difficult-to-access disclosures both in-game and on the game's official website. Significantly fewer UK games disclosed probabilities on their official websites (21.3%) when compared to 72.5% of PRC games. Only one of 75 UK games (1.3%) adopted the most prominent disclosure format of automatically displaying the probabilities on the in-game purchase page. Policymakers should demand more accountable forms of industry self-regulation or impose direct legal regulation to ensure consumer protection., Competing Interests: L.Y.X. was employed by LiveMe, then a subsidiary of Cheetah Mobile (NYSE:CMCM), as an in-house counsel intern from July to August 2019 in Beijing, People’s Republic of China. L.Y.X. was not involved with the monetisation of video games by Cheetah Mobile or its subsidiaries. L.Y.X. undertook a brief period of voluntary work experience at Wiggin LLP (Solicitors Regulation Authority (SRA) number: 420659) in London, England in August 2022. L.Y.X. has contributed and continues to contribute to research projects that were enabled by data access provided by the video game industry, specifically Unity Technologies (NYSE:U) (October 2022 – Present). L.Y.X. has met and discussed policy, regulation, and enforcement with the Belgian Gaming Commission [Belgische Kansspelcommissie] (June 2022 & February 2023), the Danish Competition and Consumer Authority [Konkurrence- og Forbrugerstyrelsen] (August 2022), the Department for Digital, Culture, Media and Sport (DCMS) of the UK Government (August 2022), PEGI (Pan-European Game Information) (January & March 2023), a member of the European Parliament (February 2023), the US Federal Trade Commission (FTC) (February 2023), and the Finnish Gambling Administration at the National Police Board [Poliisihallituksen arpajaishallinto / Polisstyrelsens lotteriförvaltning] (March 2023). L.Y.X. has been invited to provide advice to the DCMS on the technical working group for loot boxes and the Video Games Research Framework. L.Y.X. was invited to support a study on EU consumer law commissioned by the European Commission (February 2023). L.Y.X. was the recipient of two AFSG (Academic Forum for the Study of Gambling) Postgraduate Research Support Grants that were derived from ‘regulatory settlements applied for socially responsible purposes’ received by the UK Gambling Commission and administered by Gambling Research Exchange Ontario (GREO) (March 2022 & January 2023). L.Y.X. has accepted funding to publish academic papers open access from GREO that was received by the UK Gambling Commission as above (October, November, & December 2022). L.Y.X. has accepted conference travel and attendance grants from the Socio-Legal Studies Association (February 2022 & February 2023); the Current Advances in Gambling Research Conference Organising Committee with support from GREO (February 2022); the International Relations Office of The Jagiellonian University (Uniwersytet Jagielloński), the Polish National Agency for Academic Exchange (NAWA; Narodowa Agencja Wymiany Akademickiej), and the Republic of Poland (Rzeczpospolita Polska) with co-financing from the European Social Fund of the European Commission of the European Union under the Knowledge Education Development Operational Programme (May 2022); the Society for the Study of Addiction (November 2022 & March 2023); and the organisers of the 13th Nordic SNSUS (Stiftelsen Nordiska Sällskapet för Upplysning om Spelberoende; the Nordic Society Foundation for Information about Problem Gambling) Conference, which received gambling industry sponsorship (January 2023). L.Y.X. has received an honorarium from the Center for Ludomani for contributing a parent guide about a mobile game for Tjekspillet.dk, which is funded by the Danish Ministry of Health’s gambling addiction pool (Sundhedsministeriets Ludomanipulje). L.Y.X. was supported by academic scholarships awarded by The Honourable Society of Lincoln’s Inn (March 2020) and The City Law School, City, University of London (July 2020). L.L.H. declares no conflict of interest. P.W.S.N. is a member of the Advisory Board for Safer Gambling – an advisory group of the Gambling Commission in Great Britain, and in 2020 was a special advisor to the House of Lords Select Committee Enquiry on the Social and Economic Impact of the Gambling Industry. In the last five years P.W.S.N. has contributed to research projects funded by the Academic Forum for the Study of Gambling, Clean Up Gambling, GambleAware, Gambling Research Australia, NSW Responsible Gambling Fund, and the Victorian Responsible Gambling Foundation. P.W.S.N. has received travel and accommodation funding from the Spanish Federation of Rehabilitated Gamblers, and received open access fee grant income from Gambling Research Exchange Ontario. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2023 Xiao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)