Skill vs Weapon vs Attribute vs Luck

[Weylin]

This is a common debate among my group.

Which is the main factor for damage (with D&D connection):
1) the weapon itself? (die type)
2) the skill of the person using it? (BAB and amount over AC)
3) the strength of the wielder? (Str bonus)
4) a large amount of luck? (die roll)

I myself see skill as the largest factor.

-Weylin