A burgeoning literature in International Relations draws on Bourdieu’s theory of social fields to address the question of how actors make and unmake order in world politics. Inquiring into deeply seated background ideas constituting order, this literature often neglects how communication reproduces and (de)contests background ideas. Our article seeks to remedy this shortcoming by outlining a rhetorical field theory. This theory puts background ideas and foreground communication on an equal footing and conceptualises their relationship in detail. We distinguish between two layers of background ideas (nomos and topoi) and address the crucial question of how nomic change becomes possible. We introduce a typology of nomic change (destabilisation, adaption, disorientation, shift) and conceptualise the interplay of rhetorical opportunities and rhetorical moves that bring about particular types of nomic change. We probe this theoretical framework by analysing the recent nomic change in the nuclear-weapons field. This empirical analysis provides evidence for our theoretical framework.