dnd4

Intimidate is a Charisma-based skill.

Make an Intimidate check to influence others through hostile actions, overt threats, and deadly persuasion. Intimidate can be used in combat encounters or as part of a Skill Challenge that requires a number of successes. Your Intimidate checks are made against a target’s Will defense or a level-appropriate DC set by the DM (usually moderate or Hard). The target’s general attitude toward you and other conditional modifiers (such as what you might be seeking to accomplish or what you’re asking for) might apply to the DC.

Monsters can't use the intimidate skill against adventurers.

Enemy is... Will Defense Modifier
Hostile +10
Unfriendly +5

Feats

Feat Requirement Effect
Bloodthirsty Mien Charisma 15, Training in Intimidate +5 bonus when you score a critical hit
Brutal Finish Charisma 16 or training in Intimidate Reduce enemy to 0 hp using an encounter or daily attack power to impose adjacent -2 Will to adjacent enemies.
Intimidation of the Dragon Dragonborn, dragonfear, training in intimidate +4 feat bonus to Intimidate checks
Sickening Finish Training in Intimidate +1 feat bonus to defenses after dropping enemy to 0 hp.
Skins of the Slain Primal class, hide armor proficiency Feat bonus to Intimidate checks equal to 1 + the hide armor's enhancement bonus.

Intimidate utility powers

Characters trained in Intimidate may select a utility power in place of their class power (but not from a paragon path or epic destiny)

Other bonus sources