In this article we draw on the methods developed by conversation analysis and discursive psychology in order to examine how participants manage rules, fact and accountability in a specific ideological area. In particular, we focus on how participants in online discussions on veganism manage the problem posed by alleged health threats such as vitamin deficiency. We show how speakers systematically attribute responsibility for possible deficiencies to individual recipients rather than veganism. The analysis focuses on a conditional formulation that participants use in response to the recurrent question about supposed health problems in a vegan diet (for example: if you eat a varied diet, there shouldn't be any problems). This specific construction presents the absence of health problems as a predictable fact, depending on individual practices. The use of a script formulationtogether with a modal expressionenables participants to blend morality with logic, and thereby to indirectly attribute responsibility and blame to individual rule-followers. The modal construction (including qualifications as certainly, easilyand in my opinion) also allows speakers to display a concern for saying no more than they can be sure of, thus enhancing the trustworthiness of their accounts. It is suggested that this way of managing rules and accountability may also be found in and relevant for other (than) ideological domains.