Trip

Trip, as its name implies, allows you to attempt to trip an opponent.
 * Syntax :

When tripped, enemies will have a greatly reduced defensive ability and will be unable to cast spells normally.

It is harder to trip enemies that are smaller or bigger than you; being too large or small will make it impossible. Flying, swimming creatures, or creatures without legs are likewise immune to being tripped.

Using the Fly spell makes it harder for you to be tripped.

Tips

 * Some mobs have been known to cast despite sitting, don't rely on this preventing spellcasting to save your life.