Invisibility:
When cast on a hero, it renders the hero invisible.  The spell can only be cast within the range of your Wizard's Guild or Wizard Towers.  This spell is extremely useful when your hero is trying to flee and might not make it.

Farseeing:
By clicking this spell in an unexplored area, the are will suddnely be revealed.  The spell can only be cast within the range of your Wizard's Guild or Wizard Towers.  This spell is useful when you need some more space to build and there is none available due to a lack of exploration.

Ligntening:
When used on an enemy, this spell causes a bolt of lightening to strike causing significant damage.  The spell can only be cast within the range of your Wizard's Guild or Wizard Towers.

Magic Shield:
This spell causes a shield of invisible magical energy that protects the targeted hero.  The spell can only be cast within the range of your Wizard's Guild or Wizard Towers.