Fees and fairness
Fees
| Game | Fee | Where it goes |
|---|---|---|
| TailSpin | 4% of your bet, paid on top of the bet | Fee wallet. If you were referred, 10% of the fee goes to your referrer. |
| ReTail | 4% of your bet, paid on top of the bet | Same as TailSpin |
| Prophecy | A small platform fee, included in the quote | FFF |
| Prophecy legacy markets | 3% of the total pool, taken when the market resolves | FFF, the market's referrer if it has one, and a market partner |
For example, a 1 SOL TailSpin bet costs 1.04 SOL in total.
House edge on TailSpin and ReTail
Before fees, TailSpin and ReTail are fair bets. If you pick 25% odds, you win 25% of the time and get 4x your bet. On average you get back exactly what you bet.
The 4% fee is the house edge. On average you get back about 96.2% of what you pay (bet plus fee), whatever odds you choose.
| You pay | Average return |
|---|---|
| 1 SOL bet + 0.04 SOL fee = 1.04 SOL | 1 SOL |
The odds you choose change how often you win and how much, not the average.
How results are drawn
Each TailSpin or ReTail bet is settled like this:
- Your bet transaction records your odds and prize in your bet account on chain. Your bet and fee are paid at the same time.
- Fortuna's server picks a random whole number from 0 to 99, using a cryptographically secure random number generator. It draws a new number for each bet.
- The server sends that number to the Fortuna program, signed with the bet settler key (see Addresses). The program only accepts results from that key.
- You win if the number is lower than your odds. For example, at 25% odds you win on 0 to 24, which is 25 of the 100 possible numbers.
- The number is written to the program logs as "Received random value", so every result can be seen on chain.
Every bet, result and payout is recorded on Solana and can be checked. The random number itself, though, comes from Fortuna's server. Unlike FFFlip's drand flips, you can't check independently that it was drawn fairly.
If a bet is never settled
If a bet stays open and is never settled, the team can refund it. A refund returns your bet and the fee. Ask in the Famous Fox Discord if this happens to you.
Self-exclusion and blocked wallets
If you want to block your wallet from Fortuna, contact the team on the Famous Fox Discord. A blocked wallet sees a "Wallet blocked" message on the site.