In this paper, the author proposes to deal with mitigation/reinforcement phenomena in terms of ‘degrees of strength’ of speech acts, and in particular of their illocutionary force. Some aspects of the received conception of a speech act do not allow illocutionary force to vary in degree and therefore it would be inappropriate to deal with mitigation/reinforcement in traditional speech-act theoretical terms. But a revised conception of the speech act as bringing about a change in the interpersonal relationship between the interlocutors might be compatible with the results of the research on mitigation/reinforcement and even contribute to a better understanding of these phenomena. In this perspective, mitigation and reinforcement appear not as stylistic phenomena superficially adjoined to the speech act, but as the adjustment and tuning of the illocutionary effect itself. In order to show how mitigation and reinforcement can be traced back to aspects of the illocutionary act and be described by the same means by which illocutionary effects can be described, the article discusses examples of mitigation and reinforcement taken from recorded conversations in Italian.