How Case Drops Work in CS2

Every CS2 case uses a weighted random system to determine which item you receive. Items are grouped into rarity tiers, and each tier has a fixed probability range. When you open a case, the system rolls a number and maps it to a rarity tier, then randomly selects an item within that tier.

Valve has never officially published exact drop rates, but through community data aggregation and legal requirements in certain countries, we have a very good picture of the actual probabilities.

The Real Drop Rates

Based on analysis of community-tracked openings, the approximate drop rates are: Mil-Spec (Blue) ~79.92%, Restricted (Purple) ~15.98%, Classified (Pink) ~3.20%, Covert (Red) ~0.64%, and Exceedingly Rare (Knife/Gloves) ~0.26%.

This means you’ll get a knife or gloves roughly once every 385 cases on average. At current key prices, that’s a significant investment. StatTrak versions are available on approximately 10% of applicable drops, making a StatTrak knife an approximately 1 in 3,850 occurrence.

It’s important to understand that these are averages. Due to the nature of random probability, you could open a knife on your first case or go 1,000 cases without seeing one. Each opening is independent — previous results don’t affect future ones.

Expected Value Analysis

When you factor in the cost of keys and the average value of items at each rarity tier, the expected value of opening a case is typically 30-50% less than the cost of the key. In other words, for every $2.49 you spend on a key, you can expect to receive items worth roughly $1.25-$1.75 on average.

Some cases offer better expected value than others, depending on the desirability of their contents. Cases with highly sought-after knife finishes or expensive Covert skins can bring the expected value closer to break-even, but it rarely exceeds the input cost.

From a purely financial perspective, buying the specific skin you want from the market is almost always more cost-effective than trying to unbox it. Case opening is entertainment, not investment.

Wear and Float in Case Openings

When a skin drops from a case, it’s assigned a random float value within the skin’s defined range. Float values determine the wear condition: Factory New (0.00-0.07), Minimal Wear (0.07-0.15), Field-Tested (0.15-0.38), Well-Worn (0.38-0.45), and Battle-Scarred (0.45-1.00).

The float distribution is not uniform — it follows a pattern that makes extreme values (very low or very high) rarer. This is why low-float Factory New skins command premiums, as they’re statistically less likely to appear.