Yes. Every rule has a unique ID. You can see it in the URL of Launch authoring environment when you edit an existing rule.
You will see quite a few IDs on URLs as you work in Launch:
Company IDs start with CO. e.g. COca59f33b93444886915449650d242be9
Property IDs start with PR. e.g. PR74de8d4637aa4da6845d8080d3357cd1
Rule IDs all start with RL. e.g. RL1427c6546dc74b1a80c027aaf102f0de
Rule Component IDs start with RC. eg. RC7e9613780086415da3309dfd22165db3
Libraries, Environments, Extension Packages, Adaptors, all have IDs too.
You can also peek in on the Launch API calls that are being made from your browser by filtering on `adobe.io` in your browser's dev tools > network tab.
What is it that you are hoping to do with a unique rule ID?
-Stew