A smart watch and motion gaming system are disclosed. The smart watch interacts with the motion-controlled game apparatus, and includes a controller, and a geomagnetic field sensor, a gravity sensor, a gyroscope, and a data transmission circuit, which are electrically connected to the controller. The geomagnetic field sensor detects an orientation of the smart watch and acquires the orientation data. The gravity sensor detects an inclination condition of the smart watch and acquires the inclination data. The gyroscope detects a rate of rotation of the smart watch to acquire the rotation rate data. The controller runs at least one of the geomagnetic field sensor, the gravity sensor, and the gyroscope in response to the user's selection, and accordingly collect the sensing data. The data transmission circuit transmits the collected sensing data to the motion-controlled game apparatus.