Transgression through fjo̧lkynngi. Challenging the norms in Íslendingasögur. 'Magic' has a long history and the term has been employed in various contexts. Following Foucault's concept of power-knowledge, scholar Nicolas Meylan has defined Old Norse Magic as a 'constructed object of knowledge that was punctually put into discourse'. This kind of knowledge, its holders, and its manifestations have specific emic terminologies in Old Norse Literature-such as fjo̧lkynngi, 'knowledge' differentiating them from what we may call more 'regular' knowledge such as legislative, religious, scientific, etc., highlighting their ideological differences, thus their potential narrative uses, as they refer directly to the sources in their sociocultural context. Saga literature is a depiction of social cohesion and social structure in which the characters that have recourse to such knowledge are outsiders, disruptive and marginalized individuals pictured as characters who challenge normative dynamics in terms of power, gender, age, class, ethnicity, disability, and sexualities through their subversive knowledge and give us a better understanding of socio-cultural contexts in which these conceptualizations were produced. Regardless of the texts, this fjo̧lkynngi emerges as a narrative pattern, presented as the only viable option when official power and legal existing means fail to achieve the characters' agenda, whether they are protagonists or antagonists. This paper proposes to discuss conceptualizations of clandestine knowledge as a narrative tool for transgression in Old Norse Prose through several case studies of Íslendingasögur.