Dead Man's Draw ☠

Disclaimer: This project is purely experimental and a test. It is not intended for production use.

Live Demo: https://dist-cyan-pi.vercel.app

The plank's right there. And somebody's swimming home.

A pirate card game on Stellar with zero-knowledge proofs.

How to Play

What You Need

• Freighter wallet browser extension
• A Stellar Testnet account with test XLM (friendbot can fund you)

Game Flow

1. Connect Wallet — Link your Freighter wallet
2. Create or Join — Start a new game with a session ID, or join an existing one
3. Wait — The game handles seed commitment and reveal automatically
4. Draw Cards — Take turns drawing from the shuffled deck, round by round
5. Settle On-Chain — Submit a ZK proof to finalize the winner on the blockchain

The Deck

25 cards total:

Card	Count	Symbol
Rum	8	Beats Skull
Skull	8	Beats Backstabber
Backstabber	8	Beats Rum
Black Spot	1	Instant loss for whoever draws it

Winning

• First to 3 round wins takes the game
• Black Spot — draw it and you lose immediately
• Deck exhausted — if no one hits 3 wins, highest score wins; tied scores go to a deterministic coin flip

How It Works

Dead Man's Draw uses a commit-reveal scheme so neither player can cheat:

1. Both players secretly generate a random seed and commit its hash on-chain
2. After both have committed, seeds are revealed
3. The combined seeds deterministically shuffle the deck via Poseidon hashing
4. Rounds play out locally with the same logic as the ZK circuit
5. A Groth16 zero-knowledge proof is generated in-browser and submitted on-chain, proving the game outcome is correct without exposing either player's original seed

The smart contract verifies the proof and records the winner. No server ever touches the game state.

Tech Stack

• Stellar Soroban — Smart contracts in Rust (Soroban SDK 25.0.2)
• Circom + snarkjs — Groth16 over BN254 for ZK proof generation
• React + Vite — Frontend
• Freighter — Wallet integration for transaction signing
• Poseidon hashing — Deterministic deck shuffling from combined player seeds

Project Structure

pirate-zk-project/
├── circuits/               # Circom ZK circuits
│   ├── pirate_cards.circom #   Main circuit (shuffles deck + simulates game)
│   ├── deck_shuffle.circom #   Deck shuffle verification
│   └── game_sim.circom     #   Game round simulation
│
├── contracts/
│   ├── pirate-cards/       # Main game contract (create, join, reveal, settle)
│   └── mock-ohloss/        # Game Hub stub for reporting results
│
├── frontend/               # React app
│   ├── src/
│   │   ├── components/     #   UI components (Lobby, Board, WaitingRoom, etc.)
│   │   └── lib/            #   Soroban client, wallet, prover, game simulator
│   └── public/images/      #   Card artwork and background
│
├── prover/                 # ZK proving infrastructure
│   ├── build/              #   Compiled circuit (R1CS, WASM)
│   ├── keys/               #   Proving key (.zkey) and verification key
│   └── scripts/            #   Circuit build and key generation scripts
│
└── scripts/                # Contract build, deploy, and binding scripts

Getting Started

Prerequisites

• Node.js (or Bun)
• Rust + Stellar CLI
• Freighter wallet browser extension

Setup

git clone https://github.com/briwylde08/pirate-zk-project.git
cd pirate-zk-project

# Install dependencies and build/deploy contracts
bun install
bun run setup    # builds contracts, deploys to testnet, generates bindings

# Start the frontend
cd frontend
npm install
npm run dev

Environment

Create frontend/.env:

VITE_CONTRACT_ID=<your pirate-cards contract ID>
VITE_RPC_URL=https://soroban-testnet.stellar.org:443

Other Commands

bun run build          # Build Soroban contracts
bun run deploy         # Deploy to testnet
bun run test           # Run contract tests
bun run circuit:build  # Compile Circom circuits
bun run circuit:keys   # Generate proving/verification keys

Deployed Contracts (Testnet)

Contract	ID
Pirate Cards	CCIAGQ6KVIFG4OLJK7TRYMW2BPAJV5VDKK3N32LHCTV4UIZQSYKDI7AB
Mock Ohloss	CCO2UAHWVH46WI2WVXRU33LGOLWRJBXJ5KR6VQXB4GRQBKSBTBDMSD2V