A spherical weight-shifting integral free-rolling tumbler (SWIFT) is provided for rolling along a surface in a command direction. The SWIFT includes a spherical shell, a cubic box within the shell held by spars, and a controller. The box has six panels, and each panel connects to a weight-shifter. Each weight-shifter includes an actuator and a movable mass. The controller for selectively activates the weight-shifter among the panels to translate the mass from the default position to the active position. The controller operates a first switch that corresponds to panels facing away from the surface, and in combination operates a second switch that corresponds to a weight-shifter approximately facing the command direction to roll the shell accordingly.