You have an Unyielding confidence gain a +1 bonus to all die rolls when above 75% HP. When between 75-50% your confidence begins to fade, you lose your +1 bonus. When below 50 you completely lose confidence, Gain a -1 to all die rolls.
When you reach level 10 the skill changes to "You have an Unyielding confidence gain a +1 bonus to all die rolls when above 50% HP, When below 50 you completely lose confidence, Gain a -1 to all die rolls"
When you reach level 20 the skill changes to "You have an Unyielding and Unbreakable confidence gain a +1 bonus to all die rolls"