In Vlocity Context Rules, a rule set must contain more than one rule.

In Vlocity CPQ, a rule set does not necessarily need to contain more than one rule. While it's common to group multiple related rules within a rule set for organization and management purposes, a rule set can function effectively with a single rule if that is all that is required for a particular scenario. This flexibility allows for simpler or highly specific rule applications without the need for additional unnecessary rules.