Probability items must disclose drop rates

What it is

When money buys one random outcome (a pack, a wheel, a blind box, a ten-pull), people must see rates per tier before they pay—not only light and “rare guaranteed.” Disclosure is a checkable number or official table, reachable on the same layer as the purchase. It is not the virtual-currency rate, and not the no-refund clause. It is the chance itself being priced, so the chance has to be said.

Why it happens

Expected value of random rewards is inflated by spectacle, near-miss, and showcasing rares; people substitute cases (“my friend hit”) for frequencies. Without numbers, the purchase is a bet on an unknown distribution. Pity, “off-banner,” and rate-up change conditional probability; publishing only the base rate is a lie. Units must be right: single pull vs ten-pull blend, pity included or not. A table buried in a community post or a deep help article is not disclosure—digits unseen at the decision do not enter the decision.

Studying it

Give the same wheel: no rates, a base-rate table, conditional copy including pity. Watch willingness to pay and error in estimating expectation.

Independent variables: disclosure placement, pity included, whether rare showcase matches the rate. Dependent variables: expected-value estimate, number of buys, later sense of being misled.

Lab participants told to “compute expectation” over-calculate. Closer: free buying, then “about how many pulls for a rare.” Do not invent conversion or addiction percentages; probability-disclosure work cares about estimation error and informedness, not a market’s revenue figure.

Where it stops holding

Free random drops that spend nothing can disclose more weakly; spending legal tender or equivalent currency requires full disclosure. When skill or rank changes the drop, the table must be for current conditions, not one table for everyone. Where law already mandates disclosure, the table still has to be reachable at the purchase point; a statutory PDF is not a decision. For children, disclosure alone may be insufficient; parental caps still apply.

Applying it

• Put a rate table beside single-pull / ten-pull, including each rarity and pity rules.
• When rates change, update the table and stamp when it took effect; event rate-up vs permanent pool are separate.
• Do not use near-miss motion to imply the next pull is closer unless the math truly raised conditional probability and the table says so.
• Verify by covering community guides before pay: people state the top-rarity rate and pity. “By feel” or no table found fails disclosure.

Related

• Within the group: H7.15.1 Virtual currency top-up vs spend rates must be calculable · H7.15.2 No-refund rules for virtual goods must be disclosed before purchase · H7.15.3 Child IAP needs parental consent and spending caps
• Adjacent: W10.01 In-app purchase and virtual currency · H7.03 Price transparency · O4.02 Dark pattern categories
• Search terms: loot box odds · gacha probability · drop rate disclosure