Warforged enhancements (history)

Level 1
Damage Reduction I: Grants damage reduction 1/adamantine, or improves existing damage reduction by 1
 * Healer's Friend I: Benefits from healing spells increased by 10%.
 * Construct Thinking I: +2 saving throw against will-based enchantments.
 * Warforged Durability I: +2 bonus to Repair and Balance skills.

Level 2

 * Inscribed Armor I: Reduces arcane spell failure chance by 5%.
 * Warforged Hardiness: +1 bonus on Fortitude saving throws.
 * Warforged Durability II: +3 bonus to Repair and Balance skills.

Level 3

 * Warforged Constitution I: +1 constitution score.

Level 4

 * None

Level 5

 * Construct Thinking II: +3 saving throw against will-based enchantments.
 * Warforged Durability III: +4 bonus to Repair and Balance skills

Level 6

 * Healer's Friend II: Benefits from healing spells increased by 20%.

Level 7

 * Warforged Durability IV: +5 bonus to Repair and Balance skills.
 * Inscribed Armor II: Removes arcane spell failure for warforged that do not have mithral or adamantine armor.  Reduces adamantine armor feat spell failure to 25% and mithral armor feat arcane spell failure to 5%.

Level 8

 * Warforged Constitution II: +2 constitution score

Level 9

 * Construct Thinking III: +4 saving throw against will-based enchantments.
 * Warforged Durability V: +6 bonus to Repair and Balance skills.

Level 10

 * Healer's Friend III: Benefits from healing spells increased by 30%.
 * Improved Damage Reduction II: Grants damage reduction 2/adamantine, or improves existing damage reduction by 2