An actor is associated with a role, a policy type is associated with the role, and a role scope is associated with the role. One or more values are received for one or more corresponding context parameters associated with the actor. A request for access to a resource is received from the actor. A policy instance is determined based on the policy type and the one or more values for the one or more corresponding context parameters associated with the actor. One or more actor-role scope values are determined based on the role scope and the one or more values for the one or more corresponding context parameters associated with the actor. A response to the request is determined based on the policy instance and the actor-role scope values.