Rules are modular smart contracts that define custom logic and constraints across various elements like Graphs, Feeds, Usernames, and Communities within Lens. They enable developers to enforce specific conditions—for example, restricting access to a feed to users who own a particular NFT or token. This modularity allows for a high degree of customization without altering the core protocol, facilitating innovative use cases and tailored experiences within the network.

By applying rules, developers and administrators can control interactions and access, ensuring that their platforms operate according to their desired parameters. Whether it's gating content, managing membership criteria, or setting transactional conditions, rules provide the flexibility to implement complex logic in a straightforward and maintainable way.

Rules can be applied to Groups, Feeds, Graphs, and Usernames, allowing for a wide range of use cases and configurations.