About the project
Why FAIRDRUM: what it is and how it differs
FAIRDRUM (fairdrum.to) — games played for SOL tokens on the Solana network. An open smart contract takes the bets and calculates the payouts, and the independent ORAO oracle writes the random number for every round to the network. Every bet can be verified on the blockchain, the odds are the same for every player, and top-ups and withdrawals go through automatically, with no third parties. There is no registration and no token of its own. Adults only.
The facts in one table
- Network and currency
- Solana; bets, prizes and jackpots are in SOL only
- Games
- 16: Wheel, Roulette, Slots 777, Megaways, Scratch card, Blackjack, Hi-Lo, Mines, Rocket, Plinko, Tower, Dice, Heads or Tails, Limbo, Keno, Diamonds
- Bet
- from 0.01 SOL to 1 SOL per round; up to 10 SOL on the main wheel
- Where the bet goes
- about 88% to the games' prize bank, 2% to the three jackpots, 10% to the administrator
- Return to player
- about 90% of what is bet over the long run, plus the jackpot start amounts, which the project puts in from its own funds
- Round fee
- 0.005 SOL per round of any size: charged by the Solana network and the oracle, not by the project
- Top-up and withdrawal
- no project fee, one signature; withdrawal opens 12 hours after the last deposit
- Round result
- from 10 seconds to 3 minutes — the time the oracle needs to write the random number
- Login
- a Solana wallet (Phantom, Solflare, Backpack and others); no email, password or documents
- Site languages
- 14
How FAIRDRUM differs from an ordinary online casino
| Question | Typical online casino | FAIRDRUM |
|---|---|---|
| Who computes the result | The operator's server; closed code | An open smart contract; the prize tables are written in its code |
| Where the randomness comes from | A generator on the operator's side | The independent ORAO oracle: the number is written on-chain and tied to the bet |
| Where players' funds are held | In the operator’s accounts | In the contract; its code has no instruction that would hand the bank to the administrator |
| How much the operator takes | Built into each game in its own way | 10% of paid bets in all games — and nothing else |
| Account | Email, password, often documents | Not needed: you log in with a wallet |
| Withdrawal | A request, a review, timing decided by the operator | A contract transaction with no withdrawal requests; 12 hours after a top-up, a large jackpot in installments |
| How to verify a round | Trust the operator | Open the round's transactions in a Solana explorer |
| Bonuses with wagering | Yes, with conditions | No: there is nothing to wager through |
| Licence and support | Usually yes | None. The project is anonymous; nobody can reverse a mistaken transaction |
At launch we found no other project that brings all of this together: 16 games on one contract with the same average return, the same odds for every player and a bet split written into the code, starting jackpots paid from the project's funds, and not a single token of its own. Individual parts of this can be found in other projects; FAIRDRUM's value lies in the combination.
How the bet is split
The contract splits every bet at the moment of settlement: about 88% to the prize bank, 2% to the jackpot, mini jackpot and super jackpot, 10% to the administrator. The regular prizes of all games are paid from the prize bank. Each game has its own table — in some the prizes are frequent and small, in others rare and large — but the average payout per bet is the same for every table: this condition is checked when the contract is built, otherwise it will not compile.
A single prize cannot exceed a quarter of the prize bank: the contract cannot end up owing money, and a big win does not leave the bank empty for everyone else. The top prize is ×1000 of the stake; in dice, coin flip, roulette, blackjack and diamonds it is lower. The size of the bank and the pots is shown on every game page.
Jackpots: the project puts in the start amount
The project puts in the start amount of the jackpot and the super jackpot from its own funds; the mini jackpot starts at a tenth of the jackpot. After that the pots grow by 2% of every bet. After a win the pot starts again from the start amount — as long as the contract has a reserve for it.
The chance of winning a pot on one spin is written in the contract: the spin's contribution to the pot divided by its start amount. With a start jackpot of 5 SOL that is one chance in about 57,000 spins. The larger the start amount, the rarer the win. By the time it is won, a pot holds about two start amounts on average: one from the project, the other from bets. The start amount can only be changed with a 24-hour delay, and this does not affect bets already placed.
A jackpot is paid in parts: 20% at once and 8% per week. The locked part belongs to the winner and is kept in the contract.
What the project does not promise
- There is no independent audit of the contract. The code may contain a bug.
- There is no licence and the project is anonymous. In many countries games played for cryptocurrency are restricted or banned; the player is responsible for complying with the laws of their country.
- Until the program's upgrade authority is revoked, its holder can replace the code with a new version. The state of this authority is visible in a Solana explorer.
- The round's number is combined from two independent sources: the ORAO oracle and the hash of your bet's block. If the oracle has not responded within 20 minutes, the bet is refunded to your game balance in full.
- Blockchain transactions are irreversible, and there is no refund service.
- Nobody is guaranteed a win: on average players get back less than they bet.
How it was built and what guided us
Measure, don't assume
The oracle's response time and the cost of a round were measured on Solana mainnet, not taken from someone else's documentation. That is why the site says plainly: a result takes 10 seconds to 3 minutes, and the round fee is 0.005 SOL.
The site decides nothing
The site only shows what the contract computed, using the same formulas as the contract. Automated tests check that the odds on the site match the odds in the contract.
The contract's balance always adds up
A test runs tens of thousands of random operations — deposits, bets, wins, withdrawals — and after each one checks that the amount in the vault equals the sum of all the contract's obligations.
One signature per action
A deposit, a withdrawal and a round of any size take one signature each. "Play without signatures" removes the wallet pop-up for 24 hours; the temporary key can only place bets within a limit.
The price is visible before you click
Under the button of every game you can see what the round costs including the network and oracle fee, and what percentage of the stake that is. The smallest round is 0.1 SOL: the fee on it is 5%.
Limitations are on the first page
The limitations are stated plainly and gathered in one section, not in footnotes: from the 12-hour withdrawal lock to the jackpot odds.
Short summary of the project
FAIRDRUM is games played for SOL tokens on the Solana blockchain, available at fairdrum.to. There are 16 games in total: wheel, roulette, slots, blackjack, mines, rocket, Plinko, tower, dice and others. All games run on one open smart contract; the randomness for every round is supplied by the ORAO VRF oracle. Every round can be verified against the records on the blockchain, and the odds are the same for every player. Rounds start at 0.1 SOL. Of every bet, about 88% goes to the prize bank, 2% to the jackpots and 10% to the administrator; on average about 90% of what is bet returns to players. The network and the oracle charge 0.005 SOL per round. There is no registration: the player signs in with a Solana wallet. Top-ups and withdrawals are executed by the contract — automatically, with no third parties and no project fee; a withdrawal opens 12 hours after the last top-up. The project has no token of its own, no licence and no independent audit; only adults may play, and only where the law allows it.