Technical Summary

The Chainballers game is fully onchain. Each footballer is a chainballer NFT, with each players receiving 11 chainballers and 1 team NFT at registration. Chainballers attributes and looks are stored onchain, together with the team shirt pattern. The chainballer shirt will change to match the new team pattern should the footballer be traded. Moreover, the player will age onchain. The aging signs will increase with time and his skills slowly decrease. Differently from most games, the chainballers gameplay is provably fair, with the gameplay fully on-chain. A combination of unpredictable blocks data and oracle values is used to introduce randomness in matches outcome, as well as in players generation and training outcomes.

Chainballers is deployed on both Ethereum L1 and on an optimistic L2, Coinbase's Base. The game maintains value (i.e. NFTs) on a secure L1, while the gameplay is on L2 for cheaper transaction costs. Smart contracts operate an automatic L1->L2 messaging service, meaning that once NFTs are minted on L1, they are automatically reflected on the L2 to use in the game. NFT transferring is only allowed on L1, with the ownership transfer being automatically replicated on the L2. All gameplay such as league creation, lineup settings, matches and training happen on L2.