Constructor theory represents a shift from the traditional “dynamical” conception of physics—where laws predict the future state of a system given its initial conditions—to a framework based on counterfactuals. Proposed by David Deutsch and Chiara Marletto, it formulates physical laws by defining which tasks are possible (can be performed by a “constructor” with arbitrary accuracy) and which are impossible. This approach aims to provide a unified foundation for phenomena that are difficult to accommodate in standard quantum or classical mechanics, such as information, thermodynamics, and the physics of life.