This study explores how belief systems - free will, fatalistic determinism, and scientific determinism - are associated with individuals' intentions to engage in protest, focusing on the context of the 2023 earthquakes in Southeastern Türkiye. These earthquakes, with magnitudes of 7.8 and 7.5, caused severe damage and loss of life, exacerbated by issues of corruption and neglect. Drawing on collective action research, the study examines how anger and participative efficacy beliefs are linked to these belief systems and their potential role in protest intentions. The findings suggest that individuals who endorse fatalistic determinism report lower protest intentions, with anger playing a mediating role in this relationship. Scientific determinism shows a weak association with higher protest intentions, mediated by anger. Belief in free will is associated with increased protest intentions, partially through participative efficacy beliefs. The case of Türkiye, with its socio-political context and the large-scale devastation following the earthquakes, provides a meaningful backdrop for understanding how belief systems may shape protest motivations. These results offer insights into the different emotional and cognitive processes that link belief systems to protest intentions in crisis situations.