The user interface system of the preferred embodiments includes a sheet that defines a surface on one side and at least partially defines a cavity on an opposite side; a volume of a fluid contained within the cavity; a displacement device that modifies the volume of the fluid to expand the cavity, thereby outwardly deforming a particular region of the surface; and a sensor that detects a force applied by a user that inwardly deforms the particular region of the surface. The user interface system has been specifically designed to be used as the user interface for an electronic device, more preferably in an electronic device that benefits from an adaptive user interface, but may alternatively be used in any suitable application.