To illustrate how arguing actually works and how it matters we draw on a number of empirical studies that have been undertaken within a larger project on ‘Arguing and Bargaining in Multilateral Negotiations’. We discuss conditions under which arguing leads to changes in actors' persuasions and, thus, influences the process and outcomes of negotiations. These conditions refer to the institutional and normative features of the social context in which negotiations take place and characteristics of speakers and specific framing strategies they use to make arguments resonate with existing causal or normative beliefs.