JMIR SERIOUS GAMES

Ide et al

Short Paper

Adolescent Problem Gaming and Loot Box Purchasing in Video
Games: Cross-sectional Observational Study Using
Population-Based Cohort Data
Soichiro Ide1*, PhD; Miharu Nakanishi2*, PhD; Syudo Yamasaki2, PhD; Kazutaka Ikeda1*, PhD; Shuntaro Ando3,
MD, PhD; Mariko Hiraiwa-Hasegawa4, PhD; Kiyoto Kasai3, MD, PhD; Atsushi Nishida2*, PhD
1

Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan

2

Research Center for Social Science & Medicine, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan

3

Graduate School of Medicine, University of Tokyo, Tokyo, Japan

4

School of Advanced Science, SOKENDAI (Graduate University for Advanced Studies), Kanagawa, Japan*these authors contributed equally

Corresponding Author:
Atsushi Nishida, PhD
Research Center for Social Science & Medicine
Tokyo Metropolitan Institute of Medical Science
2-1-6 Kamikitazawa
Setagaya-ku
Tokyo, 156-8506
Japan
Phone: 81 3 5316 2298
Email: nishida-at@igakuken.or.jp

Abstract
Background: Video game loot boxes, which can typically be purchased by players or are given as reward, contain random
virtual items, or loot, ranging from simple customization options for a player's avatar or character, to game-changing equipment
such as weapons and armor. Loot boxes have drawn concern, as purchasing loot boxes might lead to the development of problematic
gambling for adolescents. Although parental problem gambling is associated with adolescent problem gambling, no studies haveevaluated the prevalence of loot box purchases in adolescents’ parents.
Objective: This study investigated the association between loot box purchasing among adolescents and parents, and problem
online gaming in population-based samples.
Methods: In total, 1615 adolescent (aged 14 years) gamers from Japan responded to a questionnaire regarding their loot box
purchasing and problem online gaming behaviors. Problem online gaming was defined as four or more of the nine addictive
behaviors from the Diagnostic and Statistical Manual of Mental Disorders. The adolescents’ primary caregivers were asked about
their loot box purchasing.
Results: Of the 1615 participants, 57 (3.5%) reported loot box purchasing. This prevalence did not differ according to primary
caregivers’ loot box purchasing, but adolescents who purchased loot boxes were significantly more likely to exhibit problem
online gaming (odds ratio 3.75, 95% CI 2.17-6.48).
Conclusions: Adolescent loot box purchasing is linked to problem online gaming, but not with parents’ loot box purchasing.
Measures to reduce these behaviors should target reducing addictive symptoms in young video gamers.
(JMIR Serious Games 2021;9(1):e23886) doi: 10.2196/23886
KEYWORDS
loot box purchasing; gambling; adolescents; primary caregivers

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JMIR SERIOUS GAMESIntroduction
Video game loot boxes have drawn concern over similarities
to problem gambling [1]. A gambling disorder is typicallycharacterized by adult issues with gambling. However, lootboxes feature heavily in video games marketed to children who
pay for game items/rewards with real-world currency [2]. Lootboxes contain randomized content, and therefore their value isunclear at the time of purchase. Young people are more likely
to exhibit impulsive behaviors and to find risk-taking appealing.
Therefore, purchasing loot boxes might lead to developing
problematic gambling among adolescents [3]. The relationshipbetween problem gambling and loot box purchasing appears to
be moderated by problem online gaming or excessive gaming[4,5].
The prevalence of loot box purchasing is poorly understood inadolescence. Most studies on the role of loot box purchasing in
problem gambling used adult samples [4,6,7], with only two
empirical studies utilizing adolescent samples. One study
recruited participants via an online bulletin board, which may
have included more varied gamers engaging in loot box activities
instead of only adults [8]. Another study used a community
sample from the Danish Civil Registration System [9]. However,no studies have evaluated the prevalence of loot box purchases
in adolescents’ parents, even though parental problem gamblingis associated with adolescent problem gambling [10-12]. It is
unclear whether loot box purchases among adolescents are
triggered by parental behavior or by their own problem online
gaming. Such understanding constitutes an important basis fordeveloping policies and interventions to prevent or mitigate therisks related to adolescent loot box purchasing.
This study investigated the association between loot box
purchasing in adolescents and parents, and problem online
gaming in population-based samples.

Methods

Ide et al
study on adolescents and their primary caregivers [13]. The
TTC investigates adolescents’ health and development, withthe details of the study described elsewhere [14-16]. Allprocedures involving human participants were performed inaccordance with the ethical standards of the associatedinstitutional research committees, and in adherence to the 1964
Helsinki Declaration and its later amendments or comparable
ethical standards. Informed consent was obtained from alladolescent respondents and their caregivers included in the
study. The TTC’s study protocol was approved by theinstitutional review boards of the Tokyo Metropolitan Instituteof Medical Science (approval number 12–35), SOKENDAI(Graduate University for Advanced Studies; 2012002), and the
University of Tokyo (10057).
This study sample included 2667 adolescents (aged 14 years)
born between September 2002 and August 2004, along with
their primary caregivers. Data were collected via a self-reported
questionnaire.

Procedures
In the questionnaire, adolescents and their primary caregivers
were asked whether they played online video games. Participants
who answered “yes” were defined as “gamers,” who thenanswered further questions regarding loot box purchasing. A
single question was used to determine whether they spent realmoney on items/rewards in games, excluding payment for game
consoles and software fees.
Adolescents were also asked about problem online gaming. The
proposed criteria for gambling disorder in the Diagnostic andStatistical Manual of Mental Disorders, Fifth Edition were used
to assess problem online gaming. The criteria were restated asnine questions (Figure 1) to assess the presence of certain
behaviors or emotions related to addiction in online games
within the past 12 months. Based on the proposed criteria,
respondents who reported four or more behaviors were defined
as having problem online gaming.

Participants
Data were obtained from the Tokyo Teen Cohort (TTC) study,
an ongoing, prospective, and population-based birth cohort

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Figure 1. Presence of problem gambling behaviors among adolescent gamers.

Statistical Analysis
Odds ratios (ORs) of problem online gaming according to thepresence of loot box purchasing were calculated using univariate
binomial logistic analysis. As the association between loot box
engagement and problem online gaming is stronger for womenthan men [8,9], the analysis was stratified by sex.

595 women). Of these 1615 gamers, 57 (3.5%) reported
purchasing loot boxes (4.0%, 41/1020 men; 2.7%, 16/595
women). Of the 1615 primary caregivers of adolescent gamers,
514 (31.8%) played online games and 31 (6.0%) reported
purchasing loot boxes. The prevalence of adolescent loot box
purchasing did not vary according to primary caregivers’ lootbox purchasing (χ21=0.009, P=.93; Figure 2).

Results
Of the 2619 respondents (1392 men, 1227 women), 1615
adolescents answered that they played online games (1020 men,

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Figure 2. Venn diagrams of loot box purchasing and problem gambling in adolescent gamers.

Of the 1615 gamers, 261 (16.2%) exhibited four or more
addictive symptoms in online gaming (194/1020, 19.0% men;
67/595, 11.3% women); 23 adolescents reported purchasingloot boxes and met the criteria for problem online gaming(Figure 2). Logistic regression analysis revealed that thelikelihood of problem online gaming was significantly higher
for adolescent gamers who purchased loot boxes than for those
who did not (OR 3.75, 95% CI 2.17-6.48). The OR was greaterin female gamers (OR 6.73, 95% CI 2.42-18.72) than in malegamers (OR 2.88, 95% CI 1.51-5.51).

Discussion
Principal Findings
Loot box purchasing was reported by 3.5% of 1615 gamers
aged 14 years, whereas only 1.9% of their parents reported thisbehavior. Parental loot box purchasing did not correlate withthat of adolescents. Problem online gaming was more frequently
observed, which was evident in 15.7% of adolescent gamers,
and those who purchased loot boxes were significantly more
likely to exhibit problem online gaming.
The link between loot box purchasing and problem online
gaming found in this study is consistent with previous reports
in adult populations [4,5]. As reported in previous studies [8,9],
male adolescents were more likely to be gamers and purchaseloot boxes than female gamers. However, unlike other gambling
behaviors, adolescents’ loot box purchasing does not appear to

be inherited from their parents. Measures to reduce loot box
purchases should target reducing addictive symptoms in young
online gamers.
Our study’s strength lies in confirming the absence of acorrelation between the loot box purchasing behaviors of earlyadolescents and those of their parents. Multifaceted support for
self-regulation in combination with parenting techniques forlimiting loot box purchases is recommended for children gamers[17]. Our findings suggest that parental techniques to prevent
problem online gaming may also be helpful to reduce loot box
purchases.

Limitations
This study has some limitations. The cross-sectional design did
not allow us to draw conclusions regarding the causal
relationship between loot box purchasing and problem online
gaming. A longitudinal study would be beneficial to evaluate
how loot box purchasing in early adolescence correlates withother addictive behaviors in later adolescence and with gamblingin adulthood.

Conclusions
Parental loot box purchasing did not correlate with that ofadolescents. Adolescents who purchased loot boxes weresignificantly more likely to exhibit problem online gaming.
Measures to reduce loot box purchases should target reducing
addictive symptoms in young video gamers.

Acknowledgments
We sincerely thank all of the adolescents and their primary caregivers who participated in the TTC study. This work was supported
by a Grant-in-Aid for Scientific Research on Innovative Areas (23118002 and 20616784 & 16H01689; Adolescent Mind &Self-Regulation) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. This study was also supported
by Japan Society for the Promotion of Science KAKENHI (16H06276 [AdAMS], JP16H06395, 16H06398, 16H06399, 16K21720,
and 17H05931) and AMED (JP19dk0307071) grants. Further, this work was supported in part by the University of Tokyo Center
for Integrative Science of Human Behavior. The funding sources had no roles in the study design; data collection, analysis, andinterpretation; in the writing of the report; or in the decision to publish this study.

Conflicts of Interest
None declared.
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Abbreviations
OR: odds ratio
TTC: Tokyo Teen Cohort

Edited by N Zary; submitted 27.08.20; peer-reviewed by K Magnusson, K Palmer du Preez; comments to author 14.11.20; revised
version received 26.11.20; accepted 23.12.20; published 09.02.21
Please cite as:
Ide S, Nakanishi M, Yamasaki S, Ikeda K, Ando S, Hiraiwa-Hasegawa M, Kasai K, Nishida A
Adolescent Problem Gaming and Loot Box Purchasing in Video Games: Cross-sectional Observational Study Using Population-Based
Cohort Data
JMIR Serious Games 2021;9(1):e23886
URL: http://games.jmir.org/2021/1/e23886/
doi: 10.2196/23886
PMID: 33560241

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Ide et al©Soichiro Ide, Miharu Nakanishi, Syudo Yamasaki, Kazutaka Ikeda, Shuntaro Ando, Mariko Hiraiwa-Hasegawa, Kiyoto Kasai,
Atsushi Nishida. Originally published in JMIR Serious Games (http://games.jmir.org), 09.02.2021. This is an open-access article
distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which
permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Serious
Games, is properly cited. The complete bibliographic information, a link to the original publication on http://games.jmir.org, as
well as this copyright and license information must be included.

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