A Rotational Scalar represents a single component torque acting between two bodies or on one body without a reaction torque in a particular direction. Two bodies and locations, and direction must be specified to create the torque. A Rotational Scalar object calculates its torque based on a user-specified Function Expression or User Subroutine. The action torque is applied to the action marker and an equal and opposite reaction torque is applied to the base marker. If the Only Action Body option is selected, the reaction torque is not applied to the base marker.