The Nazi occupation of Poland (1939-1945) provided a long-term proving ground for the use of unconventional and asymmetric information warfare techniques by partisan forces. The Union of Armed Struggle (Związku Walki Zbrojnej) and its more well-known successor the Home Army (Armia Krajowa) carried out a variety of innovative sabotage and propaganda operations on behalf of the Polish Underground State and the London-based government-in-exile. One of the most important fronts of these activities was resisting the harshly imposed hegemony of Nazi symbology and cultural texts within the semiosphere of occupied Poland: the ubiquitous presence of the swastika, the appropriation and Germanisation of sites of memory, and the prohibition against usage of the Polish flag and other traditional national symbols. Many of these resistance actions were carried out by the Wawer unit, a youth brigade tasked with overt propaganda activities designed to boost public morale and frustrate the occupiers. Wawer countered the texts of the occupiers with new, semiotically-honed symbols delivered to the populace in the form of graffiti and other novel methods. This paper examines these texts of the Polish resistance, which the author posits were utilised as highly effective semiotic weapons in the disruption of Nazi authority. Lotman’s conception of the semiosphere is used as a framework to model this very tangible war of texts within a concrete space: the organised efforts of the Polish underground to inject new disruptive texts into the semiotic space of occupied Poland, and the attempts to systematically purge these texts by the Nazi occupiers.