Jodobix

About

Jodobix is an experiment of a fully decentralized betting game on Optimism that doesn't rely on external parts.

Betting games are becoming more and more popular. And where I live — in Brazil — they’re causing serious debt problems because of how addictive they are.

Of course, we need better laws and education to deal with this.
But I also think most of these games are run by companies that don’t really offer anything in return. They’re just middlemen taking a huge cut.

Every year, billions of dollars go from players to game owners who do nothing but sit in the middle.

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Jodobix is a betting game that runs on Optimism. It’s fully automatic, it can’t be stopped, and it doesn’t belong to anyone — not even me.

All the money from the bets goes straight to the winners. The house takes nothing. I don’t take anything either.

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⚠️ IT'S AN EXPERIMENT

Contrary to the recommended way of picking a random number in EVM smart contracts — which relies on an external source — Jodobix experiments with a different approach. It creates a temporary winner on each bet based on the combination of the blockhash of each bet and only confirms the winner when the game encounters a hash where the last two digits are repeated. I believe there's no way to predict or avoid this moment. I've tested this theory myself, extensively trying to manipulate or predict the result. There will be a second round of tests with family and friends, and I’d like to move the project forward by talking with node specialists to understand the practical risks.

Contributing

Requirements

Before you begin, install the following tools:

• Node.js (>= v18.18)
• Yarn (v1 or v2+)
• Git

Quickstart

1. Install dependencies

yarn install

2. Run a local network

In the first terminal:

yarn chain

This starts a local Ethereum network using Hardhat. The network runs on your machine and can be used for testing and development. You can customize the configuration in packages/hardhat/hardhat.config.ts.

3. Deploy the contract

In a second terminal:

yarn deploy

This deploys the smart contract to the local network. Contracts are located in packages/hardhat/contracts, and the deployment script is in packages/hardhat/deploy.

4. Start the Next.js app

In a third terminal:

yarn start

Then visit: http://localhost:3000

To run smart contract tests:

yarn hardhat:test

5. Mock other bettors

To simulate additional bettors, run:

yarn fillgame --game-id 1

This script places a bet on each empty option.

6. End the betting period

Run the game recycler bot:

yarn gamerecycler

OR

yarn gamerecycler:opSepolia

OR

yarn gamerecycler:optimism

This bot automatically closes eligible games and creates new ones if no public open games exist.