RV12R / cardGame_Attack

We should not generate random numbers on-chain without oracle, Here we'll guess a random number of a card in a card game.

Simple Cards

So here,

• We will build a game contract where there is a pack of cards.
• Each card has a number associated with it which ranges from 0 to 2²⁵⁶–1
• Player will guess a number that is going to be picked up.
• The dealer will then at random pick up a card from the pack
• If someone correctly guesses the number, they win 0.1 ETH
• We will hack this game today :)

How we can prevent this attack

• Don't use blockhash, block.timestamp, or really any sort of on-chain data as sources of randomness.
• You can use oracles like, Chainlink VRF's for true source of randomness

Sample Hardhat Project

This project demonstrates a basic Hardhat use case. It comes with a sample contract, a test for that contract, and a script that deploys that contract.

Try running some of the following tasks:

npx hardhat help
npx hardhat test
GAS_REPORT=true npx hardhat test
npx hardhat node
npx hardhat run scripts/deploy.js