Dodging is a mechanism that allows a character to avoid being struck by some projectiles. If a projectile is not close enough to its target when it lands, it is dodged. This can be used defensively to actively move your character to avoid incoming projectiles (generally spells and arrows). Moving from side to side, activating a strong speed boost, or if you are moving laterally when the arrow is fired, the arrow will be shot towards where the game thinks you will be when the arrow lands. Simply stopping will cause the arrow to be dodged. If you don't want your projectiles dodged, either move closer or (if using a bow), use a Recurve Bow, or any bow combined with Favorable Winds or Read the Wind.
Whenever a player's projectile is dodged, he or she will briefly see yellow indicator text: "dodge".