This paper draws on the notion of the ‘project,’ as developed in the existential philosophy of Heidegger and Sartre, to articulate an understanding of the existential structure of engagement with virtual worlds. By this philosophical understanding, the individual’s orientation towards a project structures a mechanism of self-determination, meaning that the project is understood essentially as the project to make oneself into a certain kind of being. Drawing on existing research from an existential-philosophical perspective on subjectivity in digital game environments, the notion of a ‘virtual subjectivity’ is proposed to refer to the subjective sense of being-in-the-virtual-world. The paper proposes an understanding of virtual subjectivity as standing in a nested relation to the individual’s subjectivity in the actual world, and argues that it is this relation that allows virtual world experience to gain significance in the light of the individual’s projectual existence. The arguments advanced in this paper pave the way for a comprehensive understanding of the transformative, self-transformative, and therapeutic possibilities and advantages afforded by virtual worlds.