Barbarian enhancements (history)

Level 1

 * Barbarian's Action Boost I (30s cooldown): Grants 5 times/rest period the ability to receive 20s boosts to weapon damage (+2), damage reduction, or movement speed.
 * Barbarian's Intimidation: Intimidated foes are shaken
 * Barbarian's Power Attack: Additional +1 bonus to damage and -1 attack penalty with Power Attack feat active. (This enhancement will not show up on the list unless you have the Power Attack feat.)
 * Extend Rage I: Rage lasts 25% longer
 * Fast Recovery I: -20% fatigue duration after Rage (There may be a minimum constitution prerequisite for this enhancement, that is not listed on the official DDO website)
 * Skill Athleticism I: +3 on swim and jump checks
 * Skill Interaction I: +3 on intimidate and listen checks

Level 2

 * Barbarian Constitution I: +1 Constitution
 * Extra Rage I: Grants an extra Rage during rest periods
 * Power Rage I: Additional +2 Strength while in Rage
 * Resist Disease I: Grants a +3 bonus to Disease saving throws
 * Resist Poison I: Grants a +3 bonus to Poison saving throws

Level 3

 * Barbarian's Action Boost II (30s cooldown): Grants 5 times/rest period the ability to receive 20s boosts to weapon damage (+4), damage reduction (set to 8, does not stack with the barbarian's permanent DR), and movement speed.
 * Barbarian Toughness: Doubles the benefit you receive from one use of the Toughness feat. This does stack with Dwarven Toughness for a total of triple hit points from the Feat.
 * Hardy Rage I: You gain an additional +2 Constitution when raging.
 * Skill Athleticism II: +4 on swimming and jumping checks
 * Skill Interaction II: +4 on intimidate and listen checks
 * Improved Trap Sense I: +2 on all saves vs traps

Level 4

 * Extend Rage II: Your rage lasts 50% longer.
 * Greater Willpower I: You gain an additional +2 bonus to Will saves when raging.
 * Improved Damage Reduction I: You gain damage reduction 1/adamantine, or improve your existing damage reduction by 1.
 * Resist Disease II: Grants a +6 bonus on saving throws against disease.
 * Resist Poison II+ Grants a +6 bonus on saving throws against poison.

Level 5

 * Barbarian Constitution II: +2 Constitution
 * Improved Trap Sense II: Grants an extra +3 bonus on saving throws against traps.
 * Power Rage II: You gain an additional +3 Strength when raging.
 * Skill Athleticism III: +5 on swimming and jumping checks
 * Skill Interaction III: +5 on intimidate and listen checks

Level 6

 * Barbarian's Action Boost III (30s cooldown): Grants 5 times/rest period the ability to receive 20s boosts to weapon damage, damage reduction, and movement speed.
 * Barbarian's Power Attack II: Power Attack does additional bonus damage.
 * Extra Rage II: You can rage two additional times between resting.

Level 7

 * Extend Rage III: Your rage lasts 75% longer.
 * Hardy Rage II: You gain an additional +3 Constitution when raging.
 * Improved Trap Sense III: Grants an extra +4 bonus on saving throws against traps.
 * Skill Athleticism IV: +6 on swimming and jumping checks
 * Skill Interaction IV: +6 on intimidate and listen checks

Level 8

 * Barbarian Constitution III: +3 Constitution
 * Power Rage III: You gain an additional +4 Strength when raging.

Level 9

 * Greater Willpower II: You gain an additional +4 bonus to Will saves when raging.
 * Improved Trap Sense IV: Grants an extra +5 bonus on saving throws against traps.
 * Skill Athleticism V: +7 on swimming and jumping checks
 * Skill Interaction V: +7 on intimidate and listen checks

Level 10

 * Barbarian's Action Boost IV (30s cooldown): Grants 5 times/rest period the ability to receive 20s boosts to weapon damage, damage reduction, and movement speed.
 * Extend Rage IV: Your rage lasts twice as long.
 * Extra Rage III: You can rage three additional times between resting.
 * Hardy Rage III: You gain an additional +4 Constitution when raging.
 * Improved Damage Reduction II: You gain damage reduction 2/adamantine, or improve your existing damage reduction by 2.

Unconfirmed

 * Critical Rage I and II: these enhancements appear in the game files but have not been confirmed