> For the complete documentation index, see [llms.txt](https://ballman.gitbook.io/whitepaper-2023/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ballman.gitbook.io/whitepaper-2023/blockchain-contracts/the-ballman-smart-contract-cornerstone-of-the-ballman-project.md).

# The ballman smart contract, cornerstone of the ballman project

The Ballman and its basic traits and properties are defined by an Ethereum ERC-721 smart contract. As such, its properties are immutable and it benefits from all the guarantees and features expected from a standard NFT, including the ability to be sold on a marketplace like Opensea.