When case assignment rules evaluate
Key Takeaway
Whether a case assignment rule runs on a given save depends on the "Assign using active assignment rules" checkbox, the API request, or a feature such as Einstein Case Classification that calls the rule.
Case assignment rules automatically give a case an owner, based on conditions an admin defines. They can assign cases no matter how the cases are created, including cases a user creates by hand and cases created automatically, for example through Web-to-Case or Email-to-Case.
Who owns the case: a user or a queue
A case assignment rule decides who owns a case: a user or a queue. A queue lets a team work from a shared pool. Queue members can take ownership of the cases in the queue.