A weapon skill increases by fighting with a weapon of the corresponding category. Each skill has a different bonus on your stats when wearing a weapon from that category. All weapon skills can be skilled up to level 9. The first weapon skill to reach level 10 will become your specialized weapon skill and can be trained up to level 20. Let's have a look at how the different weapon skills affect your character stats.
A high Sword Skill will greatly increase your Attack Rating. If your build lacks Dexterity, specializing in this skill will make sure you won't miss your targets too often. Swords are in general much more versatile weapons than axes or blugdeons, so mastering them will also give you a notable bonus on your Armor Class. Last but not least, the skill slightly increases the damage you deal with swords.
Improving your Axe Skill will moderately increase your Attack Rating and the damage you deal when wielding an axe. Also, you'll have a small chance to deliver a critical hit with your weapon. Pick this skill for specialization if you want a more balanced bonus for your stats.
Bludgeons are bulky slow weapons used for the sole purpose to deliver heavy damage with a single blow. Specializing the bludgeon skill will maximize the damage output when fighting with those weapons. You'll also receive a slight bonus on your Attack Rating. A true damage dealer will certainly pick the Bludgeon Skill, but of course, it'll come in handy for many other builds, too.
Piercing Weapon Skill
Piercing weapons are the weapons of choice for many dexterity builds. Mastering this skill will not only increase your Attack Rating. Due to their low weight, you retain high agility when wielding a piercing weapon which gives you a slight bonus on your Armor Class, too. You won't get a damage bonus though. Instead, your chance to deliver a critical hit increases up to 6%. A dexterity build using Eagle Eye will end up with an 18% chance to do critical damage!
As with the attributes and specials, each weapon skill has a notable impact on how your character plays. Yet again, these skills can be used to compensate for any shortcomings your character might have, or to further improve his strengths. Make sure you pick the right one for specialization.