CS2 Case Opening Odds: The Real Math Behind Every Unboxing
slothiwValve publishes case odds in China due to regulation, which means the exact numbers are public — yet most players have never seen them. Here is the full probability structure of a CS2 case, and what it means for your wallet.
The official rarity odds
- Mil-Spec (blue): 79.92%
- Restricted (purple): 15.98%
- Classified (pink): 3.20%
- Covert (red): 0.64%
- Rare Special (gold — knives/gloves): 0.26%
Each tier is five times rarer than the previous one. Within a tier, every skin has equal weight; wear is then rolled on a curve that lands most drops in Field-Tested territory, and StatTrak hits about 10% of the time.
What that means in practice
Four out of five opens return a blue worth less than the key. The expected value of almost every case sits between 40% and 65% of the open cost — the house edge is structural, not bad luck. Our case opening calculator runs these exact odds against live prices for any case in the game and simulates up to 1,000 opens, so you can watch the math play out before spending real keys.
Frequently Asked Questions
What are the odds of unboxing a knife in CS2?
Roughly 0.26% per case opening — about 1 in 385 cases. The specific knife and its finish are then rolled separately, so a specific knife you want is dramatically rarer.
What is the StatTrak drop chance?
Approximately 10% of unboxed weapon skins come out StatTrak. For knives it is the same separate 10% roll.
Do more expensive cases have better odds?
No. Rarity odds are identical across all cases. Case prices differ because of what is inside the pool, not the probability structure.
