Abstract The paper focuses on the study of argumentative discourse and the deceptiveness of the fallacies. First, van Eemeren explains the meta-theoretical principles of the pragma-dialectical approach. Then he discusses the critical reasonableness conception underlying the pragma-dialectical discussion procedure based on these principles. Next van Eemeren concentrates on the ‘illocutionary perlocution’ arguing/convincing. He discusses how based on understanding the communicative act complex of arguing aims to bring about the interactional effect of accepting in the addressee. According to the pragma-dialectical theory, all violations of the rules for critical discussion instrumental in resolving a difference of opinion on the merits can be characterized as fallacies. van Eemeren makes clear how the concept of strategic maneuvering can be of help in explaining why sound and fallacious argumentative moves are sometimes hard to distinguish. The systematic incorporation of rhetorical insights in the theory makes it possible to describe more satisfactorily how fallacies ‘work’ and can be effective. Next to context-independent criteria for judging whether a rule for critical discussion has been violated in strategic maneuvering also context-dependent criteria which vary according to communicative activity type may need to be taken into account.