Minecraft wiki entry for Arrow, associated text: An arrow's speed determine the damage it inflicts. When fired from a fully-charged unenchanted bow, arrows do 6 of damage, with a smaller chance to damage for up to 11 × 5.5 via critical hits. They inflict up to 5 damage from a medium-charged bow, and 1 from a bow with no charge. Arrows fired from dispensers always do 3 of damage unless their velocity is modified by an external source. Arrows fired from crossbows do 6 to 11 × 5.5 of damage.