A rope locking device and method are provided to prevent inadvertent rope movement of counterbalanced riggings as used in theaters and auditoriums. The locking device housing is rigidly supported on a floor or wall and includes a handle to manually release a handline passing therethrough as needed. Resiliently mounted jaws with teeth within the housing adjustably grip the handline and prevent slippage thereof. When there is an out-of-balance condition, the jaws grip the handline even though the manual release handle is moved to its release position.