I went to level up Archer a bit today starting from Rank 1. I bought a Willow Shortbow to start.
Optimal Rank: 6
Attributes Quality Damage Type
Accuracy 108 Projectile 100%
Attack Power 40
Critical Hit Rate 72
*Magic Accuracy 72
*Magic Potency 5
I didn't check my stats at Rank 1 or 2, but I noticed at Ranks 3-6 my offensive stats were as follows:
Rank 3: 40%
Rank 4: 60%
Rank 5: 80%
Rank 6: 100%
When I say percentages like that, I mean I had 40/40 Atk Power at Rank 6, 32/40 at Rank 5, 24/40 at Rank 4, etc. The same held true for all of the other stats on the weapon.
I have to sleep soon and don't have the time to test at the moment, but my theory was that you take your current class rank, divide it by the optimal rank to get a percentage, and that's how effective that piece of gear is for you.
So yes, you can equip a Rank 28 item whenever you want, but from what I saw here I'd guess you only get 50% effectiveness at Rank 14 or so. 75% at Rank 21. I apologize if numbers have been published with more thorough testing already, if they have then simply disregard this =p
Edited, Oct 11th 2010 11:25pm by Jeraziah