Only one in five Hong Kong trading-card packs discloses odds of pulling a rare card

Fifty packs is a small denominator, and every one came from Hong Kong, though the researchers say the sample spanned various popular games and brands ^[1]. Twenty percent of 50 is 10 packs that printed some probability information ^[17]. The other 40 printed nothing ^[18]. The findings appear in the Journal of Behavioral Addictions, in a paper first-authored by Ching Yiu Lo ^[4]. The published summary does not say how the packs were chosen or what qualified as "some" information, so a single vague line on a wrapper may sit in the same count as a full odds table.

Per-card odds matter because of how the product is built. Collecting has surged since COVID, the researchers wrote ^[16]. Most packs hold no highly desirable card and a few do, so buyers, often children, open pack after pack chasing one ^[14]. Someone hunting one particular card needs that card's own probability to estimate how many packs the hunt will take.

The researchers set their result beside video game loot boxes. They report that 60% to 80% of important video game loot boxes now disclose probabilities, and they credit recent regulatory efforts for that rate ^[7]. The two rates come from different products and different samples. Side by side, they describe two markets at one moment. On their own they cannot show how much of the loot-box rate regulators produced.

The legal argument has two steps. The European Commission and the US Federal Trade Commission hold that consumer law already requires odds disclosure for loot boxes ^[5]. The authors then extend that view to card packs and blind boxes in the EU, the US and jurisdictions with substantially similar consumer law, Hong Kong among them ^[6]. That second step is the authors' own. The post carries a biography of Leon Y. Xiao, a Presidential Assistant Professor at City University of Hong Kong whose research the Commission and the FTC have relied on ^[13].

Beyond the retail shelf, the researchers describe third-party "repacks" or "oripas" opened online, where they say fraud is possible because a rare card may never have been inserted ^[11]. Sites such as Whatnot let several users pool money for a livestreamer to open packs, an arrangement the authors compare to betting pools ^[12]. "Just because these products have been around and socially accepted for many years does not mean that they should not now be further scrutinized," the researchers wrote ^[15].

An audit of packaging measures what the label says. It cannot show whether a printed percentage changes how many packs a buyer opens. Answering that would take a study in which one group of buyers sees the odds and a control group does not.