Watch full movie online. Mercy Rule is a baseball adventure for the whole family, starring Kirk Cameron and his wife, Chelsea. Parents and kids alike will be inspired by the story of the Miller family as they learn life’s lessons of mercy, patience, sacrifice, legacy and trusting God. Co-starring Bas Rutten and comedian Tim Hawkins and written by bestselling author N.D. Wilson, Mercy Rule will teach your family what it means to be a "No Quit Family."