Weapon Bonus vs OB

[jowe01]

When creating a new weapon, I can give it a bonus. There are two entries possible there, "Weapon Bonus" and "OB". I am not sure, what is the difference between the two? For me they are the same thing, but apparently, they are not.

[Dakadin]

Weapon Bonus is for the item's bonus. The OB is the final total that is used in the combat tracker for the attack. The weapon bonus will not show up for the players if the item isn't ID'd.

[jowe01]

Thank you for the fast answer Dakadin.

I do not really get the logic. Why should there be a field in the ITEM definition which specifies the entire OB, i.e. the OB of the wielder has with this kind of weapon if it is a variant without bonus PLUS the magic/ material/ quality bonus that the weapon gives to the wielder? The former differs from wielder to wielder, it does imho not make sense to put it into the weapon definition. I will often define a particular weapon type (eg table leg to be used as an improvised club, which I derive by duplicating and renaming the standard “club”item but adding a -20 on attack rolls) and then distribute it to several NPC who have different skills in this kind of weapon. How / why could / should I define the total OB in the item definition?