The Battleship board game is played by two players who cannot see each others’ board until the end of the game. The game operates on hidden information, and that hidden state influences each action taken by the players. The game is divided into two phases: during the placement phase, each player places k ships of varying lengths and of constant width on their board, a n X n matrix which represents a coarse discretization of the ocean. After the first phase, the game proceeds to the shooting phase, which consists of players taking turns and making guesses about the location of the ships on the opponent’s board (referred to as launching a torpedo). The guess consists of telling the opponents the coordinates [i,j] of a zone of the board. If any of the opponent’s ships are at that location, the opponent replies Hit!, otherwise Miss!. Once all the squares that the ship occupies have been hit, the ship is considered sunk. The termination of the game happens when one of the players has sunk all of their opponent’s ships and that player wins the game.
To avoid making the board visible to the opponent, the board is stored on the blockchain using the root of a MerkleTree. When both players are in the match, the game begins, and the ETH wagered will be awarded to the winner of the match.
Battleship is implemented as a DApp application, so the functions of the application are implemented through smart contracts.
The GameRule.sol contract is responsible for managing all the main functions, such as creating a new game and participating via an ID, joining randomly, and then overseeing all the game functions.
The front-end part has been implemented through an .html file and a .js file for interactions with the smart contract.
• Install Ganache to simulate the Ethereum blockchain and load the Truffle configuration file (The truffle -config.js file in the smart contract folder).
• Install Truffle to migrate the contract.
• Insert the correct port corresponding to the port present in Ganache in the truffleconfig.js configuration file.
• Install npm to execute.
• In the Battleship folder run npm ci for installing the libraries.
• In the same folder truffle migrate to deploy the contract on the blockchain.
• In the same folder, run npm run dev, at this point, the default web browser opens, displaying the main page at localhost:3000, before starting, make sure you have logged in to the Metamask extension with one of the Ganache accounts and ensure that the selected network in Metamask is localhost:7545.
• open also another browser in the same localhost:3000 and in localhost:3001, sync Options disable all. Make sure to use two different accounts.