Wisps are ancient spirits of nature that inhabit the forestlands of Kalimdor. Legends say that Wisps are actually the disembodied spirits of the Night Elves themselves, but these rumors have yet to be proven. The Wisps act in unison with the Night Elves and serve to strengthen the demigod like trees known as the Ancients. Beckoned by the Night Elves, Wisps are capable of animating various trees and expanding themselves into rough-hewn structures of living wood and stone.
Wisps do not have an attack so it is best to run away when attacked. While Wisps do not have an attack and may appear weak, they can kill the most powerful Demon in large numbers.
To mine Gold Wisps must be placed inside an Entangled Gold Mine. They cannot mine Gold from a Gold Mine until it is entangled.
Wisps are useful in battle to repair mechanical units or as a last resort to cast Detonate.
Wisps do not use up trees when they harvest which gives Night Elves the advantage of not having to seek out additional Lumber.
Because Wisps do not use up Lumber, you may find it useful to hide Wisps away from your town where the enemy is unlikely to look. If the enemy attacks your main town they won't be able to attack those Wisps harvesting Lumber.
If an Ancient is destroyed while a Wisp is constructing it, the Wisp will also be killed. If a Wisp is creating a non Ancient building such as a Moon Well it will survive if the building is destroyed while it is being constructed.
Use Wisps around the map to scout. Place several a bit outside of your town at the start of the game to watch for offensive towering. Using this method the enemy will often start building towers in your line of sight. Your Wisps will alert you to the towers because the enemy expects your town to be much further inland. The Wisps are great scouts because they can harvest Lumber while they are watching an area.
Place a Wisp in an enemy Night Elf Town. Sometimes the enemy won't even see them giving you a look into their town. This won't work against good players however.
Spell and Abilities
Renew (Autocast): Repairs friendly Night Elf buildings, allied buildings, and friendly mechanical units.
Gather: Mines gold from Entangled Gold Mines and harvests lumber from trees.
Create Building: Brings up a list of the available buildings that you may choose to create. Wisps are consumed when creating Ancients (all of the trees) but not when creating a normal structure such as a Hunter's Hall, Moon Well, or Altar of Elders.
Detonate: Destroys the Wisp, dispelling all magical buffs and draining 50 mana from each unit in an area around the Wisp. Deals 225 damage to summoned units.