Machines
A machine is a sealed pool of graded slabs with a fixed price per pull. Its cards are sorted into tiers by fair market value, and each tier has published odds stored in the machine's contract:
| Tier | Typical odds | Card value |
|---|---|---|
| Mortal | 70% | 0.2× – 0.8× the pull price |
| Hero | 25% | 0.8× – 3.2× the pull price |
| Olympian | 5% | above 3.2× the pull price |
Testnet runs six machines from 15 to 500 USDC per pull. A machine only accepts a pull while every tier has more cards than there are pulls waiting, so every pull can always be delivered. When a tier runs low the app marks the machine Restocking.
The pull
- Commit. You pay the pull price in USDC. The contract records your pull and binds it to a drand round about 3–6 seconds in the future: a random number that does not exist yet.
- The round lands. drand, a public randomness network run by independent organisations, publishes that round with a BLS signature.
- Settle. Anyone can submit the beacon (our keeper does it within seconds). The contract verifies the signature on-chain, then uses the randomness to pick your tier by the published odds and a slab within that tier.
- Reveal. The slab's NFT lands in your wallet, together with a buyback offer.
Why it is fair
- Your pull is bound to its round before anyone, including us, can know that round's value.
- The beacon is verified by the contract itself; a forged or altered value is rejected.
- The pool is fixed while pulls are pending: nobody can swap cards in or out to change your odds.
- Every pull has a page in the app's fairness verifier that redoes the math in your browser from public data.
After the pull
| Option | What happens |
|---|---|
| Keep | The NFT stays in your wallet; the slab stays in the vault. |
| Sell back | Accept the buyback offer: 85% of fair market value (capped per tier), valid for 72 hours. |
| Turbo | Choose tiers to sell back automatically at settlement, if you only want the hits. |
| Trade | List the card on the marketplace at your own price. 2% of each sale goes to the treasury. |
| Redeem | Send the NFT in with your shipping details and receive the physical slab. The NFT is burned when it ships. |
Proceeds from sell-backs and sales are credited to you in the vault; one click withdraws them to your wallet.
Real cards, 1:1
Every NFT records its custodian, the custodian's reference, the grader, grade and certificate number. A reconciler compares every live NFT with the custodian's inventory and publishes the result on the proof-of-reserve page.
Safety rails
- If a pull's drand round never arrives, you can reclaim the full price after 72 hours.
- If a redemption is not acknowledged within 7 days, you can take back the card and the fee.
- An outflow circuit breaker pauses new pulls if more than 30% of the vault leaves within 24 hours.
- Treasury withdrawals have a daily cap; admin changes go through a 48-hour timelock on mainnet.
Want the details? Read the docs or the whitepaper.