CaseBattles runs a flat 5% house edge on cases and battles, and publishes it. Most other CS2 case sites do not publish an edge; independent reviewers typically estimate them around 10%. You do not have to take anyone's word for it, though — the edge on any case is a two-minute calculation from its drop table, and this post shows you how.
What the house edge is
Every case has a drop table: each item, its value, and its drop chance. Multiply each item's value by its chance and add them up, and you get the case's expected value (EV) — what one open is worth on average. The house edge is the gap between the price and the EV. A case with an EV of 3.20 gems that sells for 3.36 has a 5% edge; the same case at 3.52 would be 10%.
Over a single open the edge is invisible — you win or you lose. Over a hundred opens it is the whole story: at 5% you expect to keep 95 of every 100 gems you put through; at 10%, 90. That difference compounds quickly if you re-open with your winnings.
How to calculate it on any site
Open a case's drop table. For each item multiply the value by the percentage (as a decimal), add the results, then divide the case price by that sum. Anything above 1.00 is the edge: 1.05 means 5%, 1.10 means 10%. Two things to watch for: sites that hide the odds (you cannot compute an edge without them), and sites that price items above market (the drop table looks generous but the “value” you win is inflated — check the item on Skinport or Steam).
On CaseBattles every case page shows each item's value and exact percentage, so you can run the numbers yourself. Try it on the Starter Kit case.
Who publishes their edge
| Site | Published edge | Odds visible per item |
|---|---|---|
| CaseBattles.gg | 5% flat | Yes, value and % on every case |
| Clash.gg | Not published (est. ~10%) | Yes |
| Hellcase | Not published (est. ~10%) | Yes |
| Datdrop | Not published | Yes |
| CSGORoll | Not published | Yes |
| Key-Drop | Not published | Yes |
| Farmskins | Not published | Reported as hidden on some cases |
As of 17 September 2026. Estimates are from independent review sites, not the operators.
Edge is not the same as fairness
“Provably fair” means the outcome of a roll can be verified after the fact — the site could not have changed the result once you clicked. It says nothing about the price. A site can be perfectly provably fair and still charge a 15% edge. You want both: verifiable rolls (see our provably fair guide) and a price you have checked against the drop table.
Other places the edge hides
Upgrader odds (ours are 100 ÷ multiplier × 0.9, shown before you roll), Double's payout table, marketplace markups on withdrawals, and crypto cash-out fees can all add cost on top of the case edge. Farmskins, for example, charges 5–10% on BTC withdrawals; Hellcase 3% on cash-outs. Read the withdrawal page, not just the case page.
Frequently asked questions
What is a normal house edge on CS2 cases?
Where reviewers have estimated it, around 10%. CaseBattles publishes a flat 5%.
How do I calculate the edge on a case?
Multiply each item's value by its drop chance, sum them for the expected value, then divide the case price by that sum. 1.05 means a 5% edge.
Does a low edge mean I will win?
No. The edge is the long-run average; any single open can win or lose. A lower edge means you lose more slowly and keep more of what you put through over time.