Guild Wars Damage Help?????

im stuck on something, when i scroll over a skill such as smoldering embers it says that it does 112 fire damage. But when i use it on a jade brotherhood knight it only does 45 why is this so and how can i fix it

Jade Brotherhood Knights have pretty good armor, so the 112 damage is reduced. The 112 damage is against someone with no armor against fire damage.

Guild Wars 330hp Rt Solo Jade Brotherhood Farm