From the handbook (Page 36):
Built by: Keep
Mage Archers are the elite Archers in Elsin’s armies. Firing slightly farther than standard-trained Archers, their arrows also inflict more damage. In addition, Mage Archers can fire three different types of arrows: Fire, Tracking and Paralyzing arrows, depending upon their target’s weak spots and the archer’s personal Mana supply.