An attachment worn against a palm side or a back side of a metacarpus of a person's hand. The attachment includes a flexible band or strip to which a sensing electronics module is attached that contains in a housing electronics for sensing gesture characteristics made by the wearer's hand, including a communications interface for communicating gesture characteristic data to a system external to the hand-worn attachment. The attachment sends at least position and orientation data in real time as a gesture is made to an external system, such as a gaming terminal. Optional sensors for detecting light, acceleration, orientation, or pressure can be used to detect other gesture characteristics and/or user inputs made while wearing the attachment. The gestures and user inputs can be used to influence graphical objects displayed on one or more displays displaying a program, such as a wagering game.