How to interpret case expected value
Case opening is not a lottery where the prize pool comes from other players — the operator sets both the price and the odds. If a case costs $5 and pays out an average of $2.50, the operator keeps $2.50 from every opening, forever. No streak, strategy or "hot case" changes that, because each opening is an independent event with the same negative expected value.
Published rarity odds let us model standard CS2 cases, while wear, StatTrak and exact rare-item probabilities still require disclosed assumptions. When odds are hidden, expected value cannot be reliably calculated. Before opening cases anywhere, check whether the site publishes probabilities and a provably fair system, and read our case opening guide for how the different case formats compare.
How prices and RTP are calculated
Expected value is the sum of each valid outcome's probability multiplied by its quoted item value. RTP divides that sum by opening cost. OpenSkin supplies separate marketplace quotes: CSFloat and Skinport use listing asks, while Steam uses its median market price. Quotes are cached hourly rather than fetched for every visit. Listing prices change with supply, demand and available inventory; they are not guaranteed cash-out values.
Rare expensive drops can raise the average far above the typical opening. Missing quotes remain visible, with probability-weighted coverage and clearly marked incomplete results. An API outage does not turn a missing skin into a zero-dollar outcome: available cached quotes remain usable with their original timestamps.
If you open cases anyway, treat the expected loss as the price of entertainment — never as an investment. Set a hard budget before you start, and read our bankroll management guide and responsible gambling resources if stopping ever feels difficult.