Guerilla Warrior
(Heroes of Battle, page 97, DnD 3.5)
[General]
You know how to move stealthily, even when armored.
Benefit
When you are wearing light or medium armor, reduce the armor check penalty of the armor by 1 (minimum 0). Hide and Move Silently ranks cost 1 skill point, even if these skills are cross-class for you. The maximum number of ranks you can purchase in a cross-class skill remains the same.
Normal
If Hide and Move Silently are cross-class skills for you, each rank you purchase in those skills without having this feat costs 2 skill points.