The classic game created into a series of smart contracts. The original contract is a basic version, then I optimize the contract for gas savings.
RockPaperScissorsSolid.sol and RockPaperScissorsHybrid.sol play the same way. The only difference between the contracts is that RockPaperScissorsHybrid.sol uses assembly blocks (yul) to save on gas costs.
A user must create a game using createGame(address _player1, address _player2) external. This function takes 2 adresses for the players and can only be called when a game is not in progress.
After a game is created both players can choose their move with playGame(uint8 _move) external payable. The cost to play is 0.05 ether and each player is only allowed to make one move. Use 1 for rock, 2 for paper, and 3 for scissors.
Once both players make their move evaluateGame() private is called to check the outcome of the game and distributes the ether to the winner, or splits the ether if the game is a tie.
If the game is taking too long any spectator can call terminateGame() external so they can play a game. In this case, the ether is sent to a player who has made their move already.
Since no data on a blockchain is truly private, an unsuspecting player can easily be taken advantage of by having their move read. scripts\hackTheGame.js shows a demonstration on how to read your opponents move. This contract is not meant to be used for competive play. It is simply a demonstartion on how gas optimizations can save the users gas.
Below shows the gas savings by using RockPaperScissorsHybrid.sol instead of RockPaperScissorsSolid.sol:
RockPaperScissorsYul.sol was created to show how the game can be written in yul. To test it, open remix and call the contract using the same paramaters for calldata. I have not tested the gas consumption as rigouriosly yet since hardhat does not support contracts fully written in yul. However here is my initial findings using remix:
playGame(uin8 _move) external payable: min: 31,480 gas, max: 39,815 gas
createGame(address _player1, address _player2) external: 71,348 gas
terminateGame() external: 29,372 gas
Contract Deployment: 349,966 gas