An arrow nock may have three or more string guide impressions that are designed to receive a portion of a bowstring to fire an arrow. Each string guide impression may be defined by two circumferentially spaced walls separated by a floor. The walls and floors may be curvilinear in shape. The walls may have sides and a peak that are curvilinear. The walls may have widths that narrow toward the peak. The walls may have a radial length that is at least one fourth of the nock outside diameter.