Heh why are you making it so complicated? Giving me a headache :p
You have two factors involved. Item Tables, and Loot Tables.
An Item Table contains a list of item IDs, as well as a low and high roll for decieding what drops. When choosing an item from the item table, a randomw value between 1 and 100 is chosen, and the item from the table which has a min/max value range covering that value is chosen. EG:
Code:
table: item_table
columns: id, item_id, min_roll, max_roll
Item Table: Medium Cloth Armor (Partial)
id=1
item_id=101 (Medium Cloth Pants)
min_roll=1
max_roll=80
id=1
item_id=102 (MEdium Cloth Shirt)
min_rill=81
max_roll=100
There is a defintion for an item table with 2 items. The pants would be the most comon drop, the shirt the more uncommon.
Assume you had a second item table with rusty weapons.
Now the second part of this scheme, is the Loot Table, which is defined in the NPC itself. The loot table is 1 entry per item you want dropped. Each entry identifies the item table to roll against, as well as the % chance that you will roll. In otherwords, you can have an 80% chance of rolling against the cloth armor table. 20% chance you won't roll on that table (And thus not have a cloth drop, but you could still have a rusty dropm as it is seperate).
This is how it is done in "real eq".