CS2 skins5 min read

CS2 case odds: what Valve disclosed about drop rates

The case odds Perfect World published for CS:GO in China in 2017, what they cover, StatTrak chances, X-ray scanners, Terminals and site cases.

Fact-checked 18 October 2026 · 8 sources

The CS2 case odds people quote don't come from Valve's own site. They come from a notice that Perfect World, Valve's licensed operator in China, posted in September 2017 because Chinese rules required it. By that notice, a weapon case gives a knife or gloves 0.256% of the time, about once in 391 openings.

Why the odds were published in China

On 1 December 2016, China's Ministry of Culture issued a notice on how online games must be run, in force from 1 May 2017. Among other things, an operator that offers random draws has to publish every item that can come out and the probability of drawing or crafting it.

CS:GO was about to launch officially in China through Perfect World. On 11 September 2017, Perfect World's CS:GO site posted a "probability notice". It didn't list odds item by item. It gave four rules:

  • Where a case can give a rare special item (a knife or gloves), rare special items and Covert items come out in the ratio 2:5.
  • From Covert down, each grade is one fifth as likely as the grade below it.
  • Items of the same grade are equally likely.
  • Where an item has a StatTrak version, it comes out StatTrak one time in ten.

The page is still online and has been kept up to date: it now lists collections and containers that didn't exist in 2017.

The odds for a key-opened case

The rules give the grades weights of 625, 125, 25, 5 and 2, from Mil-Spec up. They add up to 782, so each grade's chance is its weight divided by 782. Perfect World's own table shows the same figures.

| Grade | Weight | Chance | About 1 in | |---|--:|--:|--:| | Mil-Spec | 625 | 79.923% | 1.3 | | Restricted | 125 | 15.985% | 6 | | Classified | 25 | 3.197% | 31 | | Covert | 5 | 0.639% | 156 | | Knife or gloves | 2 | 0.256% | 391 |

A typical case holds 7 Mil-Spec, 5 Restricted, 3 Classified and 2 Covert finishes. Because items within a grade are equally likely, one particular Mil-Spec skin comes out 11.4% of the time, and one particular Covert 0.32% of the time, about once in 313 openings. The grades and their colours are covered in CS2 skin rarities and float values.

A 1-in-391 chance doesn't mean a knife arrives within 391 openings. The chance of at least one in n openings is 1 − (781/782)^n: 22.6% over 100 cases and 63.3% over 391. The published odds are the same for every opening, so a long run without one doesn't make the next case any more likely to give one.

StatTrak and wear

The StatTrak rule takes one tenth of each grade. A StatTrak Covert comes out 0.064% of the time, and a StatTrak knife 0.0256%, roughly once in 3,910 openings, in cases whose knives come in StatTrak. StatTrak and Souvenir skins explains what the counter does and where else StatTrak items come from.

Wear (the float value) and the pattern are randomised separately from the item, so the chance of one particular skin in Factory New is smaller again.

What the numbers apply to

The disclosure was made for the Chinese version of the game. As The Verge pointed out in 2017, the Chinese rule only requires odds for a game's Chinese version. Valve hasn't published a separate table for the rest of the world. When the notice came out, GameStar reported that the formula matched what players had already measured by opening thousands of cases.

Perfect World's current table groups weapon cases that need a key with the Dead Hand Terminal. Souvenir packages from Majors and map collection packages get their own lines, and the Genesis Terminal has a table with no knife or gloves: Mil-Spec 80.128%, Restricted 16.026%, Classified 3.205%, Covert 0.641%. The page adds that these are averages over a very large number of openings, and that one player's results can differ.

What a case and a key involve

Cases reach players through the weekly Care Package, a handful of random rewards to choose from, or from other players on the Steam Community Market. Opening one takes a key bought in the game. Since 28 October 2019, keys bought in the game can't leave the account that bought them: Valve made them untradable and unmarketable because, it said, nearly all traded keys by then came from fraud.

Valve has also put some new collections in Terminals rather than cases: the Genesis Collection in September 2025 and the Dead Hand Collection in March 2026. You unseal a Terminal and an arms dealer offers you one item from the collection at a time, with a price. You buy it, or decline and see the next. Dot Esports counted five offers per Terminal, and a declined offer doesn't come back. The item is still random, but you see it before you pay.

X-ray scanners in France, Germany and the Netherlands

Players in France have opened containers through an X-Ray Scanner since 2019. Valve extended it to Germany and the Netherlands on 16 March 2026. There, containers can only be opened by scanning them first, while keyless containers such as Souvenir packages are exempt. The scanner shows the item before you pay, but, as PC Gamer noted, you can't scan another container until you have bought and claimed the one already revealed. Nothing in Valve's notes says the odds change; what changes is the order of seeing and paying. How Belgium, the Netherlands and France got there is told in loot box laws and CS2 cases. Brazil's rules on loot boxes and minors are covered in Brazil's loot box ban.

How a site case with listed odds differs

Perfect World's notice gives ratios between grades, and a single item's chance follows only because items in a grade are equal. A case on a gambling site can list each item's own odds, which may differ from item to item. In cs2.casino's cases, each item owns a range of tickets out of 100,000, an opening draws ticket = floor(float × 100000) + 1, and a hash published with the case version commits to every range, so each opening can be checked afterwards.

Listing the odds doesn't make a case a good bet. A site case is priced above the average value of what's inside, and every game on cs2.casino shows its house edge; over time the house wins. House edge and RTP shows how that gap becomes an expected loss on every opening.

Sources

Read next

All posts