Sherwood Protocol // Documentation

How OutlawFlip Works

A provably fair, instant-settle on-chain coinflip game on Robinhood Chain. Stake in USDG with preset amounts ($1, $5, $10), win 1.9× in USDG — no waiting, no keeper, no VRF delay.

🔗 Network

Chain	Robinhood Mainnet
Chain ID	4663 (0x1237)
RPC	`https://rpc.mainnet.chain.robinhood.com`
Explorer	robinhoodchain.blockscout.com
Currency	ETH

📜 Contract Addresses

CoinFlipV4	`0x0DeeBdf0342757A0B14781780C0Ed942A77232Bf`
USDG Token	`0x843d02f3211a29c5CCFfD13A34BC4dab356D5Ee5`
OUTLAW Token	Not used in V4 (USDG-only)

🎮 How to Play

Connect Wallet — Click "Connect Wallet" and approve MetaMask. The app will auto-add Robinhood Mainnet to your wallet if not already configured.
Pick Stake — Choose one of three preset amounts: $1, $5, or $10 USDG.
Pick a Side — Choose HEADS (The Hood) or TAILS (The Crown).
Flip — Click "Loose the Arrow". The coin flips and settles instantly in a single transaction.
Win — If you guessed correctly, you receive 1.9× your stake in USDG, sent directly to your wallet in the same transaction.

⚡ Instant Settlement

OutlawFlip V4 uses blockhash randomness for instant settlement. The bet settles in the same transaction as the placeBet call.

1 User calls placeBet(preset, choice)

→

2 Contract transfers USDG stake in

→

3 Blockhash + win rate determines result

→

4 If won: 1.9× USDG payout sent instantly

→

5 BetSettled event emitted

All in one transaction, one block. No waiting, no keeper, no VRF delay.

💰 Payout Structure

Preset	Stake	Win Returns	Net Profit
$1	1 USDG	1.90 USDG	+0.90 USDG
$5	5 USDG	9.50 USDG	+4.50 USDG
$10	10 USDG	19.00 USDG	+9.00 USDG

Multiplier: 19/10 = 1.9×
Payout token: USDG (same as stake)
Example: Bet $5 on HEADS → Win → Receive 9.50 USDG (net +4.50).

🎛 Win Rate Control

Each preset has an independently configurable win rate settable by the contract owner (via the admin panel). The win rate is expressed in basis points (0–10000, where 5000 = 50%).

Parameter	Default	Range
$1 preset win rate	50%	0% – 100%
$5 preset win rate	50%	0% – 100%
$10 preset win rate	50%	0% – 100%

The win rate determines the probability that the player wins. At 50%, the game is a fair coin flip. The owner can adjust this per preset to control house edge and player experience.

🔐 Randomness

The result is determined by a hash of:

keccak256(
  blockhash(block.number - 1),
  block.timestamp,
  msg.sender,
  nextBetId,
  tx.gasprice
)

A random value 0–9999 is derived from this hash. If the value is less than the preset's win rate (in basis points), the player wins. The result is then set to match the player's choice (win) or the opposite (lose).

🛡 Security

ReentrancyGuard on bet function
SafeERC20 for all token transfers
Solvency check — bet rejected if contract USDG balance < payout
Ownable — only owner can withdraw, set win rates, or pause
Non-custodial — payouts sent directly to player wallet

📊 Contract Functions

Player

placeBet(uint8 preset, uint8 choice) → (uint256 betId, bool won)
  // preset: 0=$1, 1=$5, 2=$10
  // choice: 0=HEADS, 1=TAILS

Views

availableUsdg() → (uint256)
getPreset(uint8 preset) → (uint256 amount, uint32 winBps)
quotePayout(uint8 preset) → (uint256)
paused() → (bool)
nextBetId() → (uint256)
bets(uint256 betId) → (Bet)
getRecentBets(uint256 offset, uint256 limit) → (Bet[])
getPlayerBets(address player, uint256 limit) → (Bet[])

Admin (owner only)

withdrawUSDG(address to, uint256 amount)
setPreset(uint8 preset, uint256 amount, uint32 winBps)
setWinRate(uint8 preset, uint32 winBps)
setPaused(bool paused_)