Abstract Man's individual responsibility is a very central notion in Muslim theology. Rational foundations for moral responsibility presuppose, however, that man has in some way control over his actions. It was therefore of central concern to theologians to formulate theories of action that were coherent enough to account for human self-determination. This article examines al-Bāqillānī's reflections on human acts and attempts to contextualise his thought within the discussions of his time. I will briefly review the Muʿtazilites’ theory of freedom of action, against which the Ašʿarite school developed its own position. I will then outline the fundamentals of the opposing standpoint adopted by Abū al-Ḥasan al-Ašʿarī, who proposed to base human self-determination on voluntariness. Finally, I will discuss how al-Bāqillānī drew on and further developed al-Ašʿarī's ideas. Based on the extant volumes of al-Bāqillānī's Hidāyat al-mustaršidīn , I argue that he attempts to coherently organise the school's understanding of the famous theory of “acquisition” ( kasb ) by affirming two fundamental principles: a) that human acts are created by God and b) that there is nevertheless a real correlation between man and his “acquired” acts.