ChessChain is a Play-to-Earn chess platform on Solana where players earn CCHN tokens by winning games, solving puzzles, competing in tournaments, and referring friends. The smart contract (Anchor/Rust, 32 instructions) handles token presale (3-stage, SOL + USDT, anti-bot protections), airdrop distribution, reward claims, and global configuration. 10B fixed supply, mint authority revoked. Live at chesschain.club with web, PWA, and Telegram mini app.