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Hangman is the classic word game with the secret word kept encrypted on-chain. The player guesses letters, the contract checks each guess against the hidden word, and only the player can decrypt their own progress. No one, including the contract deployer, can read the word from chain state. Where Mines leans on the shuffle primitive, Hangman is a good look at the core encrypted operations. Every guess is resolved with e.eq, e.or, e.and, and e.select on encrypted values. The contract never branches on a plaintext letter.

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How it works

A HangmanFactory holds a list of encrypted words. A master account seeds them with addWord or seedWords, paying one inco.getFee() per word. Each word is a 4-character string packed into one euint256 and stored encrypted. To start a game, the factory picks a word and deploys a per-player HangmanGame, granting that game access to the chosen word. The word index is chosen pseudo-randomly from block data, but that only picks which entry to use. The word itself stays encrypted, so the selection never leaks it. The game holds all state encrypted, readable only by the player:

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Guessing a letter

guessLetter runs entirely on encrypted data:
Every result handle is granted to the player with e.allow. The frontend decrypts them off-chain to paint the board and show remaining lives. The contract stores only handles, so the word and the running state never appear in the clear.

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Running it

The repo is a Next.js frontend plus a Hardhat contracts folder. It targets Base Sepolia testnet.
Set PRIVATE_KEY, SEED_PHRASE, and BASE_SEPOLIA_RPC_URL in contracts/.env before deploying or testing.

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Honest note

This is a reference build, not a template. Words are fixed at 4 characters and a game starts with 8 lives. The word list is seeded by a trusted master account. Treat it as a worked example of doing game logic on encrypted values, not as production code.