How Upgrader Works
The Upgrader lets you risk a lower-value item for a chance to receive something better. The higher the target value compared with your source item, the lower your success chance.
How to Play
Select your source item
Choose an item from your inventory to risk. This is the item you lose if the upgrade fails.
Pick a target item
Browse the available target items and select the one you want to attempt. Higher-value targets have a lower success probability.
Review your odds
The success probability appears before confirmation. It is calculated from the ratio between the source item's value and the target item's value, adjusted for the house edge.
Upgrade
Confirm the upgrade. On success, the target item replaces your source item. On failure, you lose the source item.
Odds & House Edge
Success probability is 0.9 × source value ÷ target value. This includes a 10% house edge; the confirmed server roll determines the result.
For example, a source item worth $5 and a target worth $10 give a 45% success chance: 0.9 × 5 ÷ 10 = 0.45.
For a full breakdown of house edge across all game modes, see our What Are the Odds? page.
Provably Fair
Every Upgrader outcome on CaseRush.gg is determined using our provably fair system. Before each round, a server seed hash is published. After the round, the full server seed is revealed so you can independently verify the result was not manipulated.
The system uses HMAC-SHA256 with a combination of server seed, client seed, and nonce to generate verifiable random outcomes.
Frequently Asked Questions
How is the success chance calculated?
Success probability is 0.9 × source value ÷ target value. This includes a 10% house edge; the confirmed server roll determines the result.
What happens if the upgrade fails?
If the upgrade fails, you permanently lose the source item. The target item remains available for other upgrade attempts.
Is there a maximum upgrade multiplier?
Yes. A maximum multiplier cap keeps minimum success probabilities reasonable. The game page displays the exact cap.
Are Upgrader outcomes provably fair?
Yes. Each upgrade attempt uses the provably fair system with your client seed, the server seed, and a nonce. You can verify every completed attempt.