Ethereum Jackpot is a betting game using Ethereum as its currency for depositing and withdrawing funds.

The game is simple: several people put money in the pot. When a certain number of people have bet, one person is randomly chosen and wins the whole pot.


The probability of a player winning the jackpot is proportional to the size of his bet. For example, if other players have bet a combined value of 0.8 ETH in the jackpot, and you've bet 0.2 ETH, then you have a 20% chance of winning the whole jackpot of 1 ETH (minus a small tax).
Each player can only bet once in a jackpot.


What does 'Provably Fair' mean?

Provably Fair is a system that allows anyone to analyze the fairness of a gambling game.

This is what happens in our server in every jackpot round:

A random seed is generated on the server.
The seed is hashed using SHA-256 (the js-sha256 library is used), and the hash is shown publicly on the website.
Players bet in the jackpot. When the maximum number of bets is reached, players are assigned tickets numbered 1 - 10000 based on their bet values.
A random ticket number is generated using the seed (the seedrandom library is used). The owner of the ticket wins the jackpot.
The seed is revealed.

To verify this, there's a JS Bin sample. You can inspect its code. It uses the same libraries as the server, and will generate the same results.

Why Ethereum?

For simplicity, we decided to use only one cryptocurrency for the website. We picked Ethereum because it's widely adopted, reliable, and has low transaction fees compared to other popular cryptocurrencies (e.g. Bitcoin).

Why don't you use a smart contract?

It's theoretically possible to run the logic of jackpots inside the Ethereum blockchain itself, using smart contracts. We chose not to do this for a couple of reasons:

Ethereum smart contracts require gas to run. This means everytime a player bet in a jackpot, he would be losing ethereum as gas fee. By managing player's balances ourselves we bypass that requirement, and instead gas is only used on deposit and withdraw transactions.
We plan to possibly add other games besides the jackpot in the future. More complex games would be much harder to implement as smart contracts, so we've discarded that option from the start.


For support issues, and any questions or suggestions:

Email us at support@eth-jackpot.com