The introduction of the concept of strategic maneuvering into the pragma-dialectical theory makes it possible to formulate testable hypotheses regarding the persuasiveness of argumentative moves that are made in argumentative discourse. After summarizing the standard pragma-dialectical approach to argumentation, van Eemeren, Garssen, and Meuffels explain what the extension of the pragma-dialectical approach with strategic maneuvering involves and discuss the fallacies in terms of the extended pragma-dialectical approach as derailments of strategic maneuvering. Then they give an empirical interpretation of the extended pragma-dialectical model in which they report the testing of three hypotheses which formulate preliminary conditions for effectiveness research within the framework of the extended pragma-dialectical theory and the results of the tests they consecutively carried out.