# Optional: Set custom rule Without going into much detail on cellular automata rulesets, I want to make sure you know that at levels 16 and above, Chainlife tokens can utilize custom rules to determine the lives of their population of cells. Tokens will mature the ability to preview custom rules around level 13, and to do so, anyone can load a token, press `\` and enter a valid ruleset. `B123456/S9876542` is a valid ruleset, but it's kind of silly. `B2/S8` is a fun one. `B3/S23` is the Game of Life. All rulesets are in the format `Bn/Sn` where n are a series of digits. There is research being done in regard to these kinds of rules, as there are billions of possible combinations. You can shift your token to level 16, preview a ruleset, and if you like it, set it! If a valid ruleset is stored on chain and the token is level 16 or higher, that token will load with that ruleset as the default. Reset the on-chain ruleset by using the RESET button. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.chainlife.xyz/start-here/quickstart-guide/optional-set-custom-rule.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.