Ranks
Rank 1
You can force a target NPC at or below your level to flee for a limited time.
Rank 2
You can force a target NPC up to 10 levels higher than you to flee for a limited time.
Rank 3
You can force a target NPC up to 20 levels higher than you to flee for a limited time.
Rank 4
Intimidated targets now flee for substantial amount of time.
Challenges
Rank 1: Successfully Intimidate 5 different people.
Rank 2: Successfully Intimidate 25 different people.
Rank 3: Successfully Intimidate 50 different people.