You are in the wrong table.
KTRose uses a table called "new_drops" which does not have a field called "prob". That would be the old table "item_drops" that we don't use any more.
The server still contains the legacy code for the old drop system so it can easily be switched back and forth if you really want to.
As noted in my last post, table "new_drops" contains 201 columns. The first column is the dropid field and all the rest are pairs containing item id(x) and drop chance(x) where x = 1 to 100
the dropid field directly correlates to the dropid field in LIST_NPC.STB so when a monster dies it uses it's dropid or it's current map to select a single row from new_drops. It then drops an item from that row based on the chances listed there.
Under the new drop system, drop_rate (in config) refers to the number of items to be dropped each time a monster dies.
e.g. Set it to 10 and there will be up to 10 items dropped when you kill a monster.
This number can also be modified by personal drop rate from buffs or items such as a timed scroll.
There is a constant 80% drop chance hard coded into the server. This value is modified by a number of factors including level difference then compared against a config value BASE_DROP_CHANCE which is set from "basedroprate" in "list_config". This will be your minimum drop chance. It defaults to 20% meaning that a monster of any level will still have a 20% chance of dropping something. You can crank this up to 100% or something if you really like so that every monster you kill wil drop something. kind of messes up game play a bit IMO but it's your server so do what you like. I added the potential for it. That's as far as i need to concern myself