Salesforce Restriction Rules

Restriction Rule gives access to User/s or User/s with Custom Permission to records which has not been shared by OWD or Sharing Mechanisms.

It works contrary to what its name says.

Restriction Rule in Salesforce

Select User Criteria and a Field from User Object like Active or Custom Permission which is assigned to a User/Profile/Permission Set and than share with the Records which meets specific criteria like record isActive.