How Trade-Up Contracts Work
- Collection selection — the game randomly picks one of your 10 inputs (10% each), then randomly selects an output from that skin's collection at the next tier
- Float calculation — output wear is computed deterministically from all 10 input floats using normalized averaging
| Input rarity | Output rarity |
|---|---|
| Consumer Grade | Industrial Grade |
| Industrial Grade | Mil-Spec |
| Mil-Spec | Restricted |
| Restricted | Classified |
| Classified | Covert |
| Covert (red) | Knife/glove via 5-Covert contract (Oct 2025+) |
The Wear Formula: Relative Float Mapping
Step 1 — Normalize each input
Step 2 — Average all 10 normalized values
Step 3 — Map onto the output skin's range
Wear tier reference
| Wear | Float range |
|---|---|
| Factory New | 0.00 – 0.07 |
| Minimal Wear | 0.07 – 0.15 |
| Field-Tested | 0.15 – 0.38 |
| Well-Worn | 0.38 – 0.45 |
| Battle-Scarred | 0.45 – 1.00 |
The Filler Strategy
- Buy 1–2 expensive inputs from your target collection
- Fill the remaining 8–9 slots with ultra-cheap, ultra-low-float skins from inexpensive collections
Outcome Probability Formula
- 5 Restricted inputs from Anubis Collection (3 Classified outputs possible)
- 5 Restricted inputs from Revolution Case (3 Classified outputs possible)
Expected Value (EV) and ROI
| ROI threshold | Interpretation |
|---|---|
| < 100% | Negative EV — lose money on average |
| 100–110% | Break-even to slight edge before fees |
| > 110% | Strong candidate — verify live float-specific pricing |
Practice Free on take.skin
Case Clicker + Collection Book (simulator mode)
| Feature | What it does |
|---|---|
| Case Clicker | Earn virtual coins, open real CS2 cases at official odds, upgrade click power |
| Collection Book | First-time unbox unlocks permanent entries; rarities grant passive coin multipliers (+0.1% white through +25% gold) |
| Trade-Up tab | Select duplicate skins to craft up; 10 same-rarity → next tier |
| 5-Covert rule | Simulator-only: 5 Covert skins → guaranteed knife/glove (official CS2 requires 5 Coverts from eligible collections since Oct 2025) |
Step-by-Step: Finding a Profitable Recipe
- Open the Trade-Up Calculator
- Add planned inputs by collection and float
- Adjust float sliders — watch predicted output wear update in real time
- Check the Expected Earnings panel for ROI after live prices
- Simulate once to confirm animation and outcome distribution
- Buy inputs only after verifying float-specific listings match your model
