A method for defining and dynamically invoking polymorphic call flows in a call flow system. A publisher call flow and subscriber call flows are defined. A first trigger point in the publisher call flow is defined. Triggers specifying late-binding references to trigger points are defined in the subscriber call flows. A second trigger point in a first subscriber call flow is defined. A trigger specifying a late-binding reference to the second trigger point is defined. Publishing the call flows includes storing a second subscriber call flow's representation that includes a first trigger's representation. To execute the publisher call flow, identifiers of the publisher call flow and the first trigger point are located in the first trigger's representation. Without changing any other call flow and without terminating and restarting the publisher call flow, a call flow is added to the call flow system and invoked.