Armored Confidence (Ex)Source Armor Master's Handbook pg. 14
While wearing armor, the fighter gains a bonus on Intimidate checks based upon the type of armor he is wearing: +1 for light armor, +2 for medium armor, or +3 for heavy armor. This bonus increases by 1 at 7th level and every 4 fighter levels thereafter, to a maximum of +4 at 19th level. In addition, the fighter adds half his armored confidence bonus to the DC of Intimidate checks to demoralize him.