Spatula said:
So, what proficiency do you use in 3.5? Is a human wizard proficient with an ogre's dagger? Is a halfling rogue proficient with a human rapier?
In 3.5e, a human wizard is proficient with all daggers. However, there is a -2 penalty for each size difference; so the Human Wizard gets a -2 penalty to wield the dagger (it deals 1d6 damage).
Alternatively, by a variant rule in the 3.5e DMG, the Ogre's Dagger may be considered a Human Shortsword.
In actual fact, there are very few differences between the 3e Weapon Size rules and the 3.5e Weapon Size rules.
The actual mechanical change is to add a -2 penalty for each size difference.
The nomenclatural change is to call a dagger based on the size of the creature it is designed for, rather than it's weapon size.
So, in 3e, a dagger designed for an ogre would be a "Small Dagger", but in 3.5e it becomes a "Large Dagger", because "Large" is the size of the Ogre. I find this much easier to understand. If I mention a "Small Greatsword" in 3e, what size of creature uses it as a greatsword?
For the most part, the weapon size rules in 3.5e are used as much as the weapon size rules in 3e, which is to say: Not At All. They're used slightly more because of Halflings and Gnomes, but Halflings really benefited from the changes because (a) they got reach weapons and (b) they got Weapon Finessable weapons.
Cheers!