Skeleton archers possess the common qualities of all undead.
Immunity to mind affecting spells. Opposite effects concerning Heal and Inflict spells. Subject to Turn undead
As Skeletons they possess the same damage reduction vs Piercing and Slashing weapons. Blunt weapons do full damage as normal.
Skeleton archers are similar to their more mundane Skeltal counterparts. However they are equipped with a bow and arrows. They will use Tumble to get out of reach of Melee combatants and continue to pelt characters with a constant hail of arrows.