Overview
Every CS2 weapon case uses a fixed probability distribution to determine which rarity tier your drop falls into. These odds were confirmed through Chinese gaming regulations that required Valve to disclose exact probabilities, and have been independently verified by community data from millions of tracked openings.
Understanding these odds is essential for any CS2 player considering case openings. Whether you're a casual player curious about your chances or a trader evaluating the economics of case opening, this guide provides the complete data you need to make informed decisions.
Official Drop Rates
The following table shows the confirmed drop rate for each rarity tier. These percentages are identical across all CS2 weapon cases — the odds do not change between different cases.
| Rarity Tier | Color | Drop Rate | Avg. Opens to Hit |
|---|---|---|---|
| Mil-Spec | Blue | 79.92% | ~1.25 |
| Restricted | Purple | 15.98% | ~6.3 |
| Classified | Pink | 3.20% | ~31 |
| Covert | Red | 0.64% | ~156 |
| Exceedingly Rare | Gold | 0.26% | ~385 |
The Exceedingly Rare (Gold) tier contains knives and gloves — the most valuable items in CS2. At 0.26%, you have roughly a 1 in 385 chance per opening.
Expected Value Analysis
Expected Value (EV) measures the average return you can expect per case opening over a large number of trials. The formula is:
EV = Σ (Drop Rate × Average Skin Value for Tier)
If EV < Key Cost ($2.49), the case has a negative expected value, meaning you lose money on average per opening.
For example, consider a case where the average Blue skin is worth $0.15, Purple $3.00, Pink $15.00, Red $80.00, and Gold $1,500:
EV = (0.7992 × $0.15) + (0.1598 × $3.00) + (0.032 × $15.00) + (0.0064 × $80.00) + (0.0026 × $1,500) = $0.12 + $0.48 + $0.48 + $0.51 + $3.90 = $5.49
In this example, the EV of $5.49 exceeds the key cost, making it theoretically positive. However, most cases have significantly lower item values, resulting in negative EV.
Case-by-Case ROI Comparison
The following table compares the approximate ROI of popular CS2 cases based on current market prices. Note that these values fluctuate as market prices change.
| Case | Key Cost | Avg Return | EV | ROI |
|---|---|---|---|---|
| Kilowatt Case | $2.49 | $1.85 | -$0.64 | -25.7% |
| Revolution Case | $2.49 | $1.62 | -$0.87 | -34.9% |
| Recoil Case | $2.49 | $1.78 | -$0.71 | -28.5% |
| Dreams & Nightmares | $2.49 | $1.45 | -$1.04 | -41.8% |
| Prisma Case | $2.49 | $1.12 | -$1.37 | -55.0% |
| Clutch Case | $2.49 | $1.35 | -$1.14 | -45.8% |
As shown, all popular cases have negative ROI. The best-performing cases tend to be newer releases with high-demand covert skins.
StatTrak Odds
Approximately 10% of all case drops will have the StatTrak attribute, which tracks your kills with that weapon. This 10% applies equally across all rarity tiers.
| Item Type | Base Rate | StatTrak Rate | Price Multiplier |
|---|---|---|---|
| Mil-Spec (Blue) | 79.92% | 7.99% | 1.5-3x |
| Restricted (Purple) | 15.98% | 1.60% | 2-4x |
| Classified (Pink) | 3.20% | 0.32% | 2-5x |
| Covert (Red) | 0.64% | 0.064% | 3-8x |
| Knife/Gloves (Gold) | 0.26% | 0.026% | 1.5-3x |
How Float Values Are Assigned
When a skin drops from a case, its float value is randomly generated within that skin's allowed range. Most skins support the full 0.00–1.00 range, but some are restricted. For example, the AWP | Asiimov can only drop with floats between 0.18 and 1.00 (no Factory New or Minimal Wear).
The float value determines the exterior condition and affects visual wear on the skin. Lower floats mean less visible scratching and typically higher prices.
Check our Float Value Guide for a complete explanation of how floats affect skin appearance and pricing.
Is Case Opening Profitable?
Case opening is not profitable in the long run for the vast majority of players. The expected value of opening any CS2 case is negative, meaning you will lose money on average. The house edge ranges from 25% to 60% depending on the case.
Over 100 openings, a typical player spending $249 on keys would receive skins worth approximately $125-$175. While individual openings can yield extremely valuable items (knives worth $1,000+), these rare hits do not compensate for the consistent losses on the majority of opens.
If your goal is acquiring specific skins, buying directly from marketplaces is significantly more cost-effective. Try our Case Opening Simulator to experience the odds risk-free before committing real money.
Tips for Case Openers
- Set a budget — Decide how much you're willing to spend before you start and stick to it.
- Choose cases wisely — Newer cases with expensive covert skins offer better EV.
- Sell blues immediately — Low-tier drops lose value quickly. Sell them on the market to recover some cost.
- Track your results — Use our simulator to set realistic expectations before spending real money.
- Consider the alternative — Calculate how many skins you could buy outright with your case-opening budget.
Frequently Asked Questions
Are CS2 case odds rigged?
No, CS2 case odds are not rigged. The drop rates follow a fixed probability distribution that has been verified through millions of community-tracked openings. Valve confirmed these rates when required by Chinese gaming regulations. The odds feel unfair because the house edge is significant (40-60% loss on average), but the probabilities themselves are consistent and transparent.
What is the best case to open in CS2?
The "best" case depends on current market prices of its contents. Generally, newer cases with expensive covert skins offer better expected value. Cases like the Kilowatt Case or Revolution Case tend to have higher average returns because their rare skins command premium prices. However, even the best cases still have a negative expected value overall.
How many cases do I need to open to get a knife?
The probability of getting a knife or gloves is approximately 0.26% per opening, which means on average you would need to open about 385 cases. At $2.49 per key, that is roughly $958 spent before statistically expecting one knife drop. However, randomness means results vary widely — you could get one on your first try or go 1,000+ openings without one.
What are the StatTrak odds for case openings?
Approximately 10% of all drops from cases will have the StatTrak attribute. This applies equally across all rarity tiers. So the chance of a StatTrak Covert skin is 0.64% × 10% = 0.064%, and a StatTrak Knife is 0.26% × 10% = 0.026%. StatTrak versions are typically worth 2-10x more than their normal counterparts.
Do CS2 case odds change over time?
The fundamental drop rate percentages for each rarity tier have remained constant since they were first established. Valve has not changed the 79.92% / 15.98% / 3.20% / 0.64% / 0.26% distribution. What changes is the monetary value of items within each tier as market prices fluctuate, which affects the expected value but not the drop probabilities.
Are there better alternatives to case opening?
Yes, from a pure value perspective, buying skins directly from third-party marketplaces is almost always more cost-effective than opening cases. You can use SteamAnalyst to compare prices across 30+ marketplaces and find the best deals. If you enjoy the gambling aspect, our Case Opening Simulator lets you experience the thrill without spending real money.
➡️ Related Guides
- Case Opening Simulator — Test your luck with simulated case openings
- Case Opening ROI Calculator — Calculate expected value for specific cases
- Float Value Explained — Understand how float values affect skin pricing
